Edit: Thanks for all the suggestions and links to some great articles, they have given me the advice I think I need, so now the only thing I can do is just get out there and practice those tips. Maybe after the weekend I'll post a FR on how well I did.

My biggest problem is I can't keep a conversation going. I can talk to them, I can approach them, I am able to ask them out if I feel the right vibes, but one of my biggest reasons why I either don't talk to them or approach them is because I know I won't be able to spark up a conversation and keep it going and then i don't even bother to ask them out because I made no connection with them really. I'm bad at keeping a conversation going with people in general, but with girls it's even harder for me. Does anyone have any suggestions on how I can keep it going, or find topics that they love to talk about.

Just for more information I am a 19M I go to a university, so most of my contact with girls is either at classes or at parties.