Freshman Preparation Checklist for College Admissions

Hi,
I’m a high school freshman, and I’ve been interested in preparing for college for a little while now. I started a college fund a while ago, but is there anything more I could do to prepare?
I am interested in going to a pretty prestigious college in Canada or the USA, and if anyone could provide some advice about what I can do now to prepare for college admissions/college in general, that would be much appreciated.
Thanks so much!