start doing competitive programming as early as you can , enroll in ICPC https://icpc.baylor.edu/ and join competitive programming weekly group at you school (or start one if you don't find any)

this is a good book for preparation https://www.amazon.com/Competitive-Programming-3rd-Steven-Ha...

participate in contests on https://onlinejudge.org/, topcoder or similar on weekly basis (you will hear a lot about leetcode as a hard prerequisite to getting a job these days, but it's trivial for people who do competitive programming)

you will learn much more from doing that for a couple of years than any college can teach you