[SWTXBelle]

"Hanging out" with college boys should not hurt your chances as long as you are not doing anything with them that might lead to a bad reputation.
If you are really interested in joining a sorority, keep your grades up, be involved in activities (whether in your h.s. or the community) and read up on recruitment here on Greek Chat.
Don't worry about any perceived "dirty looks" from former high school students. While it is possible that someone who doesn't like you could try and sway the vote of her sorority, the odds are that by the time you go through recruitment most of them will barely remember you. Concentrate on presenting the best "you" that you can.
Good luck.