My dream is to become a doctor? Do i have it ?

I just finished my freshman year of high-school on all honors cles, I got a 4.023 G.P.A for the whole year. And my cl rank was 53 out of 297 students, I would like to get into a good university like Northwestern or Chicago University, but I've also taken my ACT already and have just gotten a 26. So I'm asking all of you out there, what else I would have to do through out my high-school years to get into a great university and then a good medical school. Oh and for my sophmore year I'm taking Honors Geometry, Honors English, Spanish 2, A.P. Euro, P.E, Honors Biology and Honors Religion, so tell me ?