I'm a female. And um, the girl is the president of the gay straight alliance at the college I'm attending... I know I'm overgeneralizing here but she may be gay, maybe not...
Then that's the problem. If you don't know if she's gay, then why keep your distance? Like I said before, you can start a conversation with a simple "hello" or "hi" and then go from there. You'll find out a lot about her in that short conversation with her if you know what to say. Since you said that she's the president of a club, that's a good place to start... by attending a meeting or two to see how she interacts with people. Who knows, you might see her girlfriend there too. If so, then you know she's taken and you can move on with someone else.
Let's suppose I'm gay and I like this guy who's the president of a GLBT organization. I could assume that he's gay since he's part of that organization, but I've seen white people on the eboard of black organizations and a straight student advisor for a GLBT organization. So, I shouldn't assume too quickly. Anyways, I attend this meeting to make myself possibly seen as well as having something to talk about afterwards. When the meeting is over, I approach the president and tell him, "Hi." I tell him how he seemed to do well running the meeting and how I enjoyed the meeting. "Oh, I forgot to add... my name is Ben. I'm majoring in graphic design. What about you?" "Oh, my name is Jack. I'm also majoring in graphic design too." "Really? I haven't seen you around lately. Been here long? I'm guessing you have since you are president and have earned the respect of your peers." "Oh, not really." "No? How did you come to be in this club anyway?" "Oh, my ex-boyfriend convinced me to join." "Oh, your 'ex'? Sorry about that. At least you remained stable and stayed here with the club." "Thanks. Well, I better go to class."
Well, from that short conversation (yes, I've actually learned this much from a short conversation like this before)... I've learned that he's gay or bi, is in the same major as I am, possibly supports others (he supported his ex-boyfriend when he was invited), is probably single, and is likely a good leader (he's president). Wow, I've learned a lot from that conversation. I started it with a simple "hi" and went with the flow. I didn't get too nosy since he was the one who brought up the ex-boyfriend thing. Also, mentioning your name and major is a common introductory line between college students.