Good job, now try and enjoy this summer more than any summer before, because when you get to college you never know if you have to take summer classes or a summer internship.

Honestly, don't spend time studying this summer over spending time with friends you might lose touch with when you leave for college. If you are really rusty in an area then it might be worth it to brush up but aside from thinking a bit about what field you are going to go into and your major, forget the studies for the three/four months you can.

If you go into your first year 1) refreshed and 2) having a little bit of an idea of what you are going to do then you will be able to take the generally much harder nature of college better.