help needed, i would really appreciate it!!!

I need some help!!!
Hi everyone!!! if you can please give me some information i would appreciate it so much. I am attending a community college right now and i am transfering to a university in august. I am seriously considering rushing for the fall, but i really don't know anything about the process. They had a recruitment thing on a weekend and i think that i narrowed it down to 2 sororities, because they were the only ones that actually approached us and were interested in talking to us and explaining some things, but i am still gonna keep an open mind and see what they all have to offer. The thing that i am worried about is taht i don't know what they look for in a PNM. I also read somewhere that it's not necessary but a recommendation can be very helpful, but i don't know anyone who has been in a sorority, so i am not sure what angle to go with that. And also one more thing, one of the sororites that i am considering had a member who used to be my current bf ex girlfriend, i am worried that since she has been a member with them for so long that they might not accept me, even though she isn't in it anymore, i'm not sure if she is an alumni or just simply left, and i don't even know if this should be a concern to me. So please if anyone can give me some adive on what they look for, and any other helpful information i would greatly appreciate it. THANKS!!!!

F.S