Health, that is the worst advice ever.
OP, a few of my friends went to medical school and are in the process of becoming doctors. My cousin is finishing her residency now.
My suggestion: volunteer at a clinic or as an EMT on an ambulance to get some experience in the medical field. See if you really enjoy the work.
Also, does your school offer AP exams? Consider taking AP Bio and AP Chem if they do to help move you along in school.
Additionally, if you are truly serious about this, consider going to YU/Stern for undergrade and Einstein for Medical School. There are amazing scholarships for Stern graduates and Einstein (its almost full tuition).
Becoming a doctor takes a lot of hard work and dedication getting off the ground. Its serious work. Its also extremely rewarding.
Hatzlacha!