Don't join a frat or sorority in college. I don't care if it's a 'nerdy' or 'good guys' frat at an elite university (my experience), it will be a very dumb time sink, and the networking from it is not worth it when you can get involved in other groups which offer useful connections as well.
And really, really try to become as fiercely independent as possible. Otherwise you almost certainly will start measuring yourself by others' standards, it becomes increasing worse the older you get. (You'd be surprised how common fresh out of college people think "Oh I must get into x,y,z incubator or nail down funding so I don't look like a failure and can still command lots of respect in my social circles and stand out as a 'successful young person' at parties"). It's disgusting at its worst, and it's a sufficient condition for sliding into mediocrity.