For high school students who love to program, a great activity is competing in the qualifying competitions for the USA Computing Olympiad (USACO). Even if you aren’t advanced or don’t have a lot of practice, you can enjoy the bronze and silver levels of competition. If you do really well, you can move up to the gold or even platinum competitions.
I specialize in training students who are just starting out or have enough experience to enjoy the bronze and silver levels of competition.
Experience in these competitions is a good way to stand out on a college application.