I want to become a surgeon.?

I am in the 8th grade. My average grades are usually B+ and above. I have a strong interest in becoming either a cardiac surgeon or a pediatric surgeon - like neonatal - so could I? I know I a really young to be thinking about this, but I really want to step up my game and become a surgeon. What courses should I take in high school. There is a pre-med program I am interested in. I'm guessing I should also do advanced sciences. What should I aim for grade wise to achieve the intelligence I need to become a surgeon? Also, If you live in the South Florida area, I have gotten into St. Andrew's School, American Heritage, Cardinal Newman, and The King's Academy. Which one do you think would help me achieve my goal better? Is there anything else I can do to reach my goal?