How do I use the Raycasting Engine?

There should be a couple of paragraphs about what does what in the first about 100 lines or so, just go look in Slot 1 once you've loaded it.

That doesn't help.

I need each function explained better

That's about all your gonna get sadly

So I'm guessing I'm never going to create a game like Wolfenstein 3D

I'll try to make my own 3d engine

Not with this language... it’s not powerful enough. And with the raycaster, you should replace LOAD with USE and then remove the USE 1. It will be faster and more efficient.