One step at a time...
The vast majority of pre-college pre-meds end up changing their minds long before med schools give the thumbs up or thumbs down. So at this point, you should have both a Plan A (physician) and a Plan B (something else) and give them both serious work and planning, with the Plan B possibility being treated as the significantly more likely of the two, because at this point, it is.
So for now -- What would you want to do if you couldn't become a doctor? Head in that direction, while ALSO taking the science courses you will need as a pre-med. If your Plan B is to become a chemist, great -- no extra work. If your Plan B is investment banking, do well in those courses and ALSO do well in Bio and Chem for science majors and all bases are covered.
Re-evaluate after your freshman year. Is med school even an option still? (GPA still good?) Do you WANT it to be? Gradually shift your emphasis as you have more information to work with because a BA in biology and a sub 3.0 GPA is NOT going to get you where you want to be...