One thing I can say for sure. Everyones experience is different. Your GPA from power school doesnt mean a thing. How you apply yourself and how you go about things really determines your abilities here.
1) Dont be shy. Get over that crap with a quickness if you are
2) DONT BE SHY!!! Talk to your instructors, they are there for a reason.
3) GO FIND MM1 Palmer. He will take care of you, hes a great guy and really smart. He was one of my counterpoints in the navy when I was in. He WILL take the time to teach you, any day of the week.
4) dont be afraid to get dirty during cleaning stations. Those coveralls are meant to get dirty.
5) Get some comfortable boots
6) resist the temptation to cheat on the computer tests (you will see!!!). I saw a LOT of kids get screwed hard because of that.
7) dont make an example of yourself. OR make an example of yourself. If you dont understand my point, then dont make waves

Those books arent a mystery, you need to learn to use them at some point, so why not now?
Hours are 12 hour days, I've never heard of 16 hour days at prototype.