i want to become a pediatrician, what classes in high school should i take? And what electives would you prefer that i do?
In the US school system, you should aim to just do the best you can overall, making sure you're strong in the sciences especially. Your high school classes will have minimal impact on your medical school application.
There is not a very strong linkage between how to apply to college, and what you do after college. It's probably true that someone looking to be a newspaper journalist after college probably as a slight to moderate career advantage by focusing in English in high school, but it's not that much. Not nearly as much as what classes you take during college, and more importantly, how you search for the job. (Exception: if you are applying to a joint Bachelor MD program, you should look at the requirements of that joint program).
Generally, you want to get into a good college, which will have a rigorous science program that will get you into the medical school you want. To do this, you can do really anything to get into that college. In other words, your high school classes only affect your medical career insofar as it affects the college you get into.
However, insofar as you want a preview of what preparing for medical school would be like, taking biology (and all the sciences) is a good idea. As well as taking math (but not nec the hardest math). Being generally well-rounded is a good idea too.