How to become a doctor?

I want to pursue a career in medicine. Like the doctors that do check-ups and such. I would like to open my own medical center one day. I am 16. I have a 3.0-4.0 GPA but in my upcoming junior year, I will make it a goal to maintain a 4.0 throughout my...

remaining high school years. What exactly do I do to pursue my dream of becoming a doctor?

You apply to a good undergraduate program to get your bachelors degree. This degree is usually a bachelors in science, you can major or minor in anything you want. Most people are usually biology majors because of the number of classes you need, and a minor in chemistry usually happens automatically, but again it is up to you. There will be a pre-med program that you can follow to make sure you get the all the requirements, they'll tell you what classes you need to take and what not. Then you take the MCAT and start applying to medical schools...

Go to college?

I don't know, actually... I mean, the brazilian system is different from the american teaching system, so I'm not sure what to do =(

life science.
and then you apply for medical school.