How do I get to US uni (Stanford, UCLA,etc,) with A-level?

Hey guys
I just finished my AS and when I got my grades this summer, I felt that I kind of messed up and decided to retake my A-level. I guess it will be difficult with A-level system changing and all that, but I think I could have done better.
Anyway, what I am confused about is, how do students in UK get into US uni. I heard they require GPAs, APs, and some honor courses (don't really know). How does A-level grades match with this?
Also I have hopes to get into Stanford (at least it is my goal), does anybody what grades and things i have to do? For example, 4 A* and sports activites etc.
Thanks for reading and i would be very grateful for replies.

P.s. Can anybody help me out with getting financial aid on US unis? Don't get how it works

Reply 1

someday16

Thanks for your reply
If I get AAB in Math, History, Economics respectively, and A*A*A in A2 plus SAT score about 2200, what do you think are my chances of getting into Stanford? If it is not enough what universities would it be appropriate?

Reply 2

someday16

Sorry, but I am not sure if I am understanding this correctly. so AAB in AS is more like NYU level universities??
And it would be great if you could tell me how much the elite universities regard extracurricular activities like sport in their admission process.

Reply 3

someday16

This is more challenging than i had anticipated...Sorry to bother you with so many questions, but I plan to resit my AS economics and history(they are not the best grades) and do A2 at the same time. If this is the case how should i submit my grades in the application this fall? Do I submit the grades i Got this summer or do i give them the predictions AS grades of resit next year + prediction of A2 grades? And would this look very bad to uni?

Reply 4

someday16

That's quite depressing...i wanted to make up my AS results with resits. Just another question. I recently got a chance to transfer to a school with americal curriculum(nearly everything same as a us highschool). Would it be better to transfer to this school if i want to go to US uni?
Would this look bad in applying?