Hey Drew,
The main difference between FDM printers (like the Ender) and SLA/Resin printers such as the Eleegoo Mars is in terms of resolution and model size.
Basically if you want to make track, buildings, train bodies and other large parts then FDM is probably the best route. The Creality Ender series are consistently reasonably good and I've had a number of models over the years, however my current favourite go to FDM printer is a Tronxy XY-2SE. This I like because it has all the goodies that are often extras on other printers such as some of the enders including auto-levelling, dual vertical screws (keeps the horizontal print bar level) and at least for me a consistent level of printing reliability. In the past I found myself constantly having to fix or adjust things on the Ender's, on the Tronxy the only thing I eventually had to change was the nozzle and then subsequently the hot end 'throat'. That problem I will likely fix eventually by changing it to an all metal hot end such as the ones made by Micro-Swiss. These look expensive at first, but if it means you don't get failed prints or blockages during a print they are worth it.
If however you want to make smaller or highly detailed parts the SLA/Resin printers are the route to go. These print at a much higher resolution than any FDM printer and sometimes can even be quicker as they print a whole layer in one hit, whereas with an FDM printer it effectively has to trace out the entire layer before moving to the next one. Resin prints can also be more robust depending upon how they are printed, although with very fine detail they can sometimes have parts snap off if they are fine as the resin is often more brittle than the plastic used in an FDM printer which generally has a level of flexibility to it.
In terms of consumables? Well on an FDM printer you would likely want to use either a PLA or maybe one of the PLA+ filaments. Personally I've found some of the PLA+ types to be a bit troublesome as they often require higher temperatures to work well and this can cause issues if you don't have an all metal hot end fitted as it can damage the lining of the hot end throat (this is the metal tube that runs through the heatsink and into the heat block and butts up against the nozzle. These are frequently lined with Teflon, but unfortunately if you run a filament that needs a higher temperature (ABS is a prime example as are some PLA+) you can get 'heat creep' from the block up into the heat sink via the throat which eventually results in damage to the teflon at which point the filament if it gets too hot can start to stick to the inside of the throat. If this happens the only realistic option is to replace the throat, not massively expensive, but if it starts to play up when you are say 20 hours into a big print it is not only frustrating, but also expensive due to the replacement parts and wasted filament. So for the most part I would stick with a good PLA at least till you get used to the system, PETG is probably the next best option as this can offer more robust prints, but is a little more difficult to use and can especially suffer from 'stringing' - that is fine threads of plastic sometimes generated when the print head moves across the model while not actually printing. With judicial tuning you can minimise this, but it can take a lot of time to get right and can vary from one brand of PETG to another brand. As for brands, one of my favourites is 'Ziro' I find their product to be consistent in quality and reliable. Other brands are good also, including the Eono and Overture brands (Owned by Amazon), Sunlu and Creality themselves also make some good filaments. You should also be aware that there are 'silk' variants of PLA as well as standard PLA. These are beautiful to look at and if you can get the printer dialed in right can produce some stunning prints. But they are more difficult to use than standard PLA and can have de-lamination issues resulting in less robust prints. The bottom line is get a printer, buy a few different rolls of PLA from different brands and try them, you will soon find the ones that are more consistent/reliable than others. Just don't go buying multiple rolls until you find the ones you like
Resin printers are a lot easier in terms of consumables, most brands of UV resin will work in most printers, at worst you may have to play around with exposure time settings etc... although I've found most work with the default values without an issue. You can also get some special resin variants claiming to be more resilient, more flexible or similar, these can be better than standard resins, but you need to try them to see how well they work for you. The other main difference is post processing. With an FDM printer once its finished you just pop the print off the bed, clean up any supports you may have used and maybe sand down any imperfections before painting. With a resin/SLA printer post processing is quite an involved process. With traditional resin you need to wash the finished prints thoroughly using isopropyl alcohol (called 'rubbing alcohol' in the USA), this removes the unexposed liquid resin, then you have to thoroughly wash the prints in water to remove the alcohol, finally the print needs to be exposed to a UV light source to 'cure' the resin fully. During all this process you need to wear rubber gloves and preferably some protective glasses and possibly a mask to prevent getting the uncured resin on your skin/eyes/mouth. It is pretty nasty stuff and can cause burns or whatever if you get it on your naked skin. There are automated machines you can get that get round most of this hassle, but it is still a pain in the backside having to take all these precautions, however the results are generally worth it. One of the more recent innovations is a water based resin, this is slightly easier to use as you just have the water washing stage, followed by the curing. However some people claim the quality isn't as good, I'm not so sure, I've had no major complaints myself when I've tried it.
So there you go, a brief dump of knowledge. But basically - big prints or things like track use FDM/PLA, if you have detail parts, model people, or small items the SLA/Resin is probably best. For train bodies either is possible, although generally I've used FDM, same is true of carriage bodies or wagons.
The main difference between FDM printers (like the Ender) and SLA/Resin printers such as the Eleegoo Mars is in terms of resolution and model size.
Basically if you want to make track, buildings, train bodies and other large parts then FDM is probably the best route. The Creality Ender series are consistently reasonably good and I've had a number of models over the years, however my current favourite go to FDM printer is a Tronxy XY-2SE. This I like because it has all the goodies that are often extras on other printers such as some of the enders including auto-levelling, dual vertical screws (keeps the horizontal print bar level) and at least for me a consistent level of printing reliability. In the past I found myself constantly having to fix or adjust things on the Ender's, on the Tronxy the only thing I eventually had to change was the nozzle and then subsequently the hot end 'throat'. That problem I will likely fix eventually by changing it to an all metal hot end such as the ones made by Micro-Swiss. These look expensive at first, but if it means you don't get failed prints or blockages during a print they are worth it.
If however you want to make smaller or highly detailed parts the SLA/Resin printers are the route to go. These print at a much higher resolution than any FDM printer and sometimes can even be quicker as they print a whole layer in one hit, whereas with an FDM printer it effectively has to trace out the entire layer before moving to the next one. Resin prints can also be more robust depending upon how they are printed, although with very fine detail they can sometimes have parts snap off if they are fine as the resin is often more brittle than the plastic used in an FDM printer which generally has a level of flexibility to it.
In terms of consumables? Well on an FDM printer you would likely want to use either a PLA or maybe one of the PLA+ filaments. Personally I've found some of the PLA+ types to be a bit troublesome as they often require higher temperatures to work well and this can cause issues if you don't have an all metal hot end fitted as it can damage the lining of the hot end throat (this is the metal tube that runs through the heatsink and into the heat block and butts up against the nozzle. These are frequently lined with Teflon, but unfortunately if you run a filament that needs a higher temperature (ABS is a prime example as are some PLA+) you can get 'heat creep' from the block up into the heat sink via the throat which eventually results in damage to the teflon at which point the filament if it gets too hot can start to stick to the inside of the throat. If this happens the only realistic option is to replace the throat, not massively expensive, but if it starts to play up when you are say 20 hours into a big print it is not only frustrating, but also expensive due to the replacement parts and wasted filament. So for the most part I would stick with a good PLA at least till you get used to the system, PETG is probably the next best option as this can offer more robust prints, but is a little more difficult to use and can especially suffer from 'stringing' - that is fine threads of plastic sometimes generated when the print head moves across the model while not actually printing. With judicial tuning you can minimise this, but it can take a lot of time to get right and can vary from one brand of PETG to another brand. As for brands, one of my favourites is 'Ziro' I find their product to be consistent in quality and reliable. Other brands are good also, including the Eono and Overture brands (Owned by Amazon), Sunlu and Creality themselves also make some good filaments. You should also be aware that there are 'silk' variants of PLA as well as standard PLA. These are beautiful to look at and if you can get the printer dialed in right can produce some stunning prints. But they are more difficult to use than standard PLA and can have de-lamination issues resulting in less robust prints. The bottom line is get a printer, buy a few different rolls of PLA from different brands and try them, you will soon find the ones that are more consistent/reliable than others. Just don't go buying multiple rolls until you find the ones you like
Resin printers are a lot easier in terms of consumables, most brands of UV resin will work in most printers, at worst you may have to play around with exposure time settings etc... although I've found most work with the default values without an issue. You can also get some special resin variants claiming to be more resilient, more flexible or similar, these can be better than standard resins, but you need to try them to see how well they work for you. The other main difference is post processing. With an FDM printer once its finished you just pop the print off the bed, clean up any supports you may have used and maybe sand down any imperfections before painting. With a resin/SLA printer post processing is quite an involved process. With traditional resin you need to wash the finished prints thoroughly using isopropyl alcohol (called 'rubbing alcohol' in the USA), this removes the unexposed liquid resin, then you have to thoroughly wash the prints in water to remove the alcohol, finally the print needs to be exposed to a UV light source to 'cure' the resin fully. During all this process you need to wear rubber gloves and preferably some protective glasses and possibly a mask to prevent getting the uncured resin on your skin/eyes/mouth. It is pretty nasty stuff and can cause burns or whatever if you get it on your naked skin. There are automated machines you can get that get round most of this hassle, but it is still a pain in the backside having to take all these precautions, however the results are generally worth it. One of the more recent innovations is a water based resin, this is slightly easier to use as you just have the water washing stage, followed by the curing. However some people claim the quality isn't as good, I'm not so sure, I've had no major complaints myself when I've tried it.
So there you go, a brief dump of knowledge. But basically - big prints or things like track use FDM/PLA, if you have detail parts, model people, or small items the SLA/Resin is probably best. For train bodies either is possible, although generally I've used FDM, same is true of carriage bodies or wagons.
Happily collecting things all my life... 
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