From what I have seen and what I have been told by my DS:
Take Calculus is you can. AP is even better. He was able to get credit for 1st semester Calculus with what he learned in AB. He has a Squad mate who got credit for both semesters of Calculus from what he learned in BC. They don't really look at the AP score, placement is done via an exam you take before you arrive on I Day. Doolie year is hard enough so any credits you can get are always plus.
You will have to take one Computer Science class as part of the Core curriculum. More if you go into any Computer Science or Engineering Major. Having a basic programming class in HS gives you a head start and may make it easier (again Doolie year is a culture shock so anything that makes it any easier is a plus). DS's High school didn't offer any AP Computer Science so he took two AP classes online offered through Rice University. His college counselor at his school had to set it up for him but the classes have helped him a lot.
As others have said. Take the hardest classes your High School has to offer, especially in Math and Science (Chemistry and Physics)
Good Luck!