I have general admission (pit) tickets to Post Malone should I go early for good spots? And how close is GA(pit) to the stage?

Both questions can vary with each individual show. The pit is usually within a foot or two of the stage. Some shows have stage extensions and barriers. I would call the box office if I were u.

Pit is in front of the stage but you should go early, regardless, as parking in the garages can fill up fast. There are lots of restaurants around so you can eat first, then go.

Is there roof area on the ga pit spot?

Do you think people will do overnights to get good GA seats?

I don't know the answer