I think that you should google “Applying sideways, MIT” (or follow the pointer below), and read the blog that it takes you to. It describes pretty much exactly what I did to get accepted to MIT, and what some other family members have done to get accepted to highly ranked universities.
The main point is that I did nothing at all for the purpose of getting accepted to MIT. My wife did nothing to get accepted to an Ivy League graduate program. My older daughter did nothing to get accepted to a “top 5” DVM program. Instead, we each did what was right for us, whatever that was. What I did to get into MIT was completely different from what some others have done to get into top schools, but it was right for me.
If you are the sort of student who will do well at a highly ranked university, then “what is right for you” will include taking at least some tough classes and doing very well in them. It will include participating in some activities and doing well in them also, and will include treating people fairly. You also should have some humility while you are doing very well in whatever you are doing. Certainly if you make it to MIT or Harvard or Stanford then these schools have a way to teach a student a bit of humility (for example, if you are the #1 or #2 student in your high school, then you can expect to be only average the day that you show up on campus). You should understand that “leadership” means listening and making an activity better for everyone who participates in that activity. Leadership is not about doing things your way.
A good “spike” for applying to top universities is to live your life well, and to do whatever you do well. Also find some time to have a bit of fun along the way.
Someone else talked about “ORIE”. The “OR” part is Operations Research, which is what I got my master’s degree in. It is pretty much applied mathematical methods for solving problems. At least in my opinion it is both great fun and a great way to make a living. Doing well in math in high school is a good start in this direction. Doing well in math includes making sure that you have a solid foundation and that you understand the concepts. It does not require jumping way ahead.
I agree with all of this. You have a lot of time to figure this out. Keep and open mind and keep ahead in your class work and you should do well.