The first thing you need to do is not get ahead of yourself. Going from seeing a girl to banging her is a process.
If you approach a woman the only thing you should be doing is seeing if she is interested... then if she is available... then if she gives you her number.... next will she meet you on a date.... does she actually show up and not flake. I don't care what PUAs say, you can not make anything happen with any woman want. A woman has to want what you have or you are just wasting your time. It is a numbers game, in college you should be trying to strike up conversations with any girls you are attracted to then see how she responds. Trust me... this is a lot easier than focusing on one woman and busting your @ss trying to make something happen.
Only when she is willing to meet you alone on a date do you have something to work with.... at that point is is all about not screwing up. As far as what you can do in college... well... I don't know where you are, but where I went there was ALWAYS something going on that didn't require money... free movies, parties, sporting events, extracurricular activity, you don't have to go to a bar or club. Figure out what you like to do and invite her along. If she doesn't like you she won't go, then you just move on to the next one. If she likes you, she'll go along with your plans to see if her assumptions are confirmed.
Get involved with activity in college that has nothing to go with PlayStation or X-Box, every university has many clubs and organizations that have nothing to do with Greek culture. Join something you like and this is the best way to meet college girls because you have built in rapport.
There are times when a woman will just meet you and you end up in bed, but really that doesn't have anything to do with you, it's her and where she is in that emotional moment, you really don't have any control over this accept not fvcking it up.