I think you are very wise to be thinking ahead and trying to use your high school time wisely. My suggestion is that you start investigating choices for a nursing school
and to look at the courses they require. Use that information to help you choose your high school classes.
For example, most RN programs require students to take courses in anatomy and physiology, english, statistics, pharmacology, history, etc. at the college level. However, some students assume that because they are going to go to "nursing school," and not "regular college" they don't need to take the tough college-prep courses their high schools
offer. When they get to nursing school, they find themselves unprepared to do college-level work.
Most nursing ARE "regular college" and require the student to take some of the same college classes that people in other majors take. Becoming a good, strong student with a well-rounded academic background in physicial sciences, social sciences, and humanities is the best thing you can do for yourself. Then you will be prepared to succeed in school -- AND as a nurse.