Help a CS major

After lurking these forums for years, I've decided to finally ask a question: So I'm a CS major (freshman) at a lower/mid-tier Ivy looking for some guidance. I'm most interested in algorithms/game theory/econometrics/numerical methods, you know, the quanty stuff. I was wondering what the best careers would be for a cs major interested in working in wall street. I've seen a lot of terms thrown around, like algo trading, exotics, FICC, blah blah, but it all confuses me terribly. What's the difference between prop and algo trading? What are the different desks in BB trading? Definitely recommend me fields where a CS background is very useful for. What should I be doing in college as well? I love to read Yahoo Finance and The Economist.