Definitely try formal and go in with an open mind - I went through recruitment a month ago and found my home in a very unlikely chapter (definitely not the chapter I thought I wanted to be a part of going into recruitment) and I LOVE IT!
Remember that everything happens for a reason and you do end up where you belong... on the otherside though, also remember that joining a sorority isn't for everyone. Either way, consider getting involved on campus between now and then - it can't hurt!