Any experience with cnc-step machines?

Easy way:
-download the official ISO from the downloads page, burn it to USB, boot the PC from it
-test as much as you like, start the includes sim (simulated) configurations, they do everything without a machine attached
-get an old PC with a parallel port or get an add on parallel card
-get some cheap TB6600 drives and motors
-cobble something together so it moves, some short rails and belts should do just fine
-enjoy, you will learn more form doing this than reading for months
=
If you feel like it, get a used industrial machine, plenty of those where you live, preferably with dead controls, retrofit it with Mesa boards, make chips/art/decor/money
Can be found from 1-5K, another 700-1200 for Mesa, PC, cables, ferules, crimp tools, maybe power supplies and other stuff.
You end up with a magnificent machine.
And sorry but i have to say this: requires absolutely following advice from others here. This is where some fail miserably, luckily very rarely.