spring vs. fall rush

I'm a freshman who did not want to rush back in the fall, but now that I know myself and what I want better, I want to be in a sorority. I heard that rushing as a sophomore is looked down upon, but I don't know which sororities are doing spring rush (although I could email and ask), and I would want to be able to check all of the houses out so I know I end up in the right place. Thoughts?