College Advice

For those of you who have actually worked in the field, what kind of suggestions or advice could you give to a college freshman going into Computer Science? Things to do in spare time, what's important to learn and what isn't, fields to look into, etc etc, whatever you find relevant.

(P.S. My college teaches C, I've been programming since high school, and I have been reading SICP)

If Java is so dumbed-down and bloated, and C++ is so bad, why are all the major software projects these days apparently using them?

Also, when I say "expert of Java" i mostly just mean get good enough at it and know enough of what I can do with it so that I can write better code than other Java programmers. One of the things I'm hoping learning C and reading SICP/TAOCP will help me with