At what point does causation/ contingency end? Where does it stop?
Depends. If the universe is eternal, it never stops. If the universe had a beginning, it stops at that beginning.
And as for me telling you to get an education, that's a fair comment. If you think Craig's evangelical version is even worth giving serious consideration, then you need a real education. Craig is not a scientist, he just plays one on TV.
Even if the universe is eternal, that doesn't beget it came from nothing, or 'just exists'. The universe, if current science be right, is very contingent on natural law, which is eternal regardless of the universe existing or not.
Why does electromagnetism work? And why does it always follow the 'rules' of it's nature? Smae with gravity, motion, etc.
It's hard to make a case for the universe as brute fact when all the 'stuff' in it, and that which makes it up and defines it is all contingent. I don't see how one can make a case where the very thing that defines the universe is contingent, but the universe itself is not.
In fact, the universe is contingent on what is in it. Without matter and energy, there is no universe, no time, nothing.