I would like to learn 3d printing before I purchase any 3d equipment. The local library has a 3d printer I can use, but I don't know where to get "patterns" "programs" or parts to manufacture. I don't even know what to call the program the 3d printer follows.

can i change the scale of existing programs? are they available online?

I know these are basic questions, but if you guys ever need to know anything about concrete construction just ask, i see the benefit of reddit is to be able to reach out to experts in all fields.