Northwestern University- HPME

Hello!
I am a high school freshman in a highly competitive vocational technical school where there is a major focus on the sciences and mathematics. I am aspiring to become a doctor and recently learned of the HPME program at Northwestern University. It seems to be a really great fit for my personality due to the goals of flexibility and inquisitiveness. May someone please tell me what I should do to be accepted into the program!
Thank you!