help a freshman out

I postponed getting involved in rush to focus on grades and now I'm really regretting it. I guess it's mainly because as the rest of my friends go through spring pledgeship, I have less and less of a social life. I'm a freshman by the way, and I am definitely looking to get involved in greek life. So please help me out people because I don't wana be a GDI who watches Game of Thrones on a Friday night when I could be at a pair.
A few questions:
Do I have to wait till next fall to try to rush, or are there any opportunities as the school year is closing?
If not, is rushing as a sophomore frowned upon?
In your opinion, whats your favorite few frats that have a pretty good rep and have cool brothers?
Thanks in advance.