@aynsley683 … As you could be asking about several things, I will give it a shot, and you can then clarify.
#1 – Do you mean "I am thinking about getting my own 3D printer and know almost nothing about them. My intended purpose is to print my own terrain for ancients in several sizes. How do I learn more about 3D printers in general?"
Google is your friend. Go searching for 3D printing tutorials. You will find loads of blog posts and articles. Some generic, and some written by people who got a printer for the same reason as you … to print gaming terrain.
But in general, there are a couple of different types of printers. The most common (cheapest) is one that lays a thin layer of hot plastic down, and builds up the desired item one layer at a time. Those are FDM printers. A number of types of plastics can be used, but the standards are PLA and ABS. One is easier to work with but more fragile, the other is harder to work with (requires an heated enclosure to do properly), but hardier. There are other types as well.
Another type of printer uses resins. Those are more expensive, harder to work with and clean up, but can provide a better final product. Those are usually called SLA printers.
So go look for reviews of top FDM or SLA printers, get a feel for the terminology, the costs, and the final product produced.
Side Note: I went with FDM. I am interested in terrain, not actual humanoid figures. I don't think the tech is there yet to produce a good looking 30mm figure with a face, etc. But the tech is easily there to make dungeon walls, caverns, brick houses, roads, fences, etc.
#2 – Do you mean "I want to print terrain for ancients, in both 15mm and 25mm. How do I find people who have designed the .STL files so I can buy them, and then print my own?"
Many people with talent have been designing files for a few years now, and more are joining in. I started out by thinking maybe, just maybe, I would learn the complicated software, and design my own stuff. I quickly realized it was far easier and cheaper to pay someone else to do a much better job for me.
You can again goole looking for terrain files. They are generally called .STLs (at least for FDM printers). There are kickstarter campaigns all the time offering new sets of terrain files for relatively cheap, considering how much you get.
Go check out Printable Scenery. They have lots and lots of terrain for many periods. It will give you an idea of what is out there and the detail available.
A recent campaign was All Roads Lead To Rome. Check out that campaign here. Lots of photos. You can find their web site too.
link
If you are getting a printer, you can try out free files by going to Thingiverse. Once there, type in something like ancients and see what pops up. If you enter something like Dungeons you will find loads of free files to make dungeon (or fortification/castle) walls.
Without paying to buy something specific, you can download these files for free, and get used to playing and calibrating and working your printer, so you can get an actual "product" in your hands, and see just how cool it is.
You can track down more "ancients" files over time.
#3 – Do you mean "I want to learn how to make my own files" then others will need to chime in. Several good (and free) cad programs, but learning how to make a square might be easy. Texturing it, and making connections, then adding a doorway, plus a door, etc … that is when it gets harder. Not my thing. But others here like to do that sort of thing.
So please clarify what you meant by your initial posting, and helpful people can jump in with more pointers!
