Most students in upper secondary schools lose a lot of opportunities to separate them from another university degree.
Take a university teacher now
Not after you related to Princeton, but before.
Why does this help?
1) It shows your amazing initiative on going beyond what is required
2) Suppose you are good at these categories (A and C grade) university level – one key factor for Ivy League admission requirements
3 ) It shows you the criteria for where you need to be in your studies – which will, conversely, help your learning materials and your results in regular kindergartens. After all, if you can be successful in college classes, AP courses seem like a joke
4) It opens the world of other university opportunities – such as the ability to build relationships with professors who can write recommendations, employment and research authorizations and so on. More about it later
5) University teaching can open up new areas of interest to you and a new passion. You get to explore the stuff that high schools can't offer, it's a big luxury
Then go out and do it! Especially if you are a junior high school or senior, I suggest that you study homework. Not a university, but a local university. Don't forget about other things like outside activity and community service, but look at courses at universities now.
There is a huge edge in entry, but it requires a lot of work. Get started now and prepare for the start of college.