Highschoolers wanting to enter Med school?

I just finished my sophomore year, and now am entering my junior year. It is my life dream to become a successful doctor! Never once have I doubted myself with medical school, and I do understand the harsh reality of it! Still, mediciine is something I want to do! I wish to apply to some of hte prestigious colleges like Duke, Cornell and maybe UC Irvine for preMed! Is there anything I can do during my junior year to get these coleges to notice my genuine passion of bcoming a doctor! I heard ideas like writing essays, is there anything else? i wish my school had activites or groups that had stuff to do with medicine, i just have this PASSION for it! I cant explain, which kind of does not help me when the time comes to write a personal statement for UNI! i'd appreciate the help! Thanks!