These not only offer you a strong foundation, but show you different opportunities that you might be interested in pursuing.
Every High School and College requires different courses to graduate so you won't have to worry about specialized science classes until your Jr. or Sr. year of High School. As long as you are taking biology and chemistry to start you will be fine.
It depends on what specialization you are going to get in the future since medicine includes various branches. In many cases, medicine is related to biology, health science, cardiology, and so on.
All the best