You’re on the right track. Keep up the grades, and deepen and expand your ECs a bit more. It’s quality over quantity, so you don’t have to pick up something new (unless you want to) so much as continuing to find ways to grow and challenge yourself (USACO is a nice start).
Don’t start a club to get a title, but do start one if there is an unmet and ongoing need in your school, and you are absolutely committed to filling that void - and you expect the club will be sustainable after you graduate. Lots you can do with coding.
Even XC shows colleges your social skills in a way that your coding has not, and you’ll probably make varsity as an upper classman.
It isn’t always about who has the most titles and awards. Consider how you are stretching via each activity and what actively participating in them says about you as a person (and is that person the one you want to present to colleges?). How will bringing those qualities to the table make a positive contribution to the college community where you land? Will that match what the colleges are looking for?
Sophomore year is a great time to make a plan, and it isn’t unchangeable. Expect to revise it as necessary in light of new information and opportunities.