Math classes should not be taken over the summer, ever! You want as much time to digest and practice as you can. This is especially true since there are no SAT subject tests to take right after your summer school.
Geometry is a very unique class in high school. It teaches problem-
Statistics is extremely useful in college for most majors, even those that may not seem to be math-
Calculus is very different from most other math classes, and many students struggle with it because their teachers fail to explain what calculus really is and what it tries to solve. If you find that you don’t understand why you are doing certain things, ask about it. Having an understanding of “why” can really help you learn calculus. Otherwise it becomes a whole bunch of memorization which is not how math should be taught. Memorization may get you good test scores in class, but you will not do well on the AP Exams.