Fabian D.
Well, that depends on what you need. If it´s something "simple" (regular patterns, wheels, basic furniture, geometric shapes) CAD-programs are the way to go. Everything else (figures, complex curved objects) should be created with other tools (either done by scanning real objects or using other graphic programs (Blender for example)).

I haven´t worked with eiter of the later alternatives, but the process after that is the same as if you´ve created you model with a CAD program. As I´m told you have to save it in the required format, run and pass some checks, meet a few more criterias, select the material and other specfications and place your order... probably the easiest part of the deal.

If we go for the CAD option (easier to see succsess there😉 ) you need to aquire a program first, which shouldn´t be a problem. There are even legal and free options out there. Once you´re familliar with your program you can most likely answer both of your questions on your own.😉 I´ll get you a link to the program I´m currently using.