My suggestions:
First, go to the mall, sit down, and watch what young women your age are wearing.
Then go to some thrift stores (Good Will, Value Village, Salvation Army). Buy a few things that you saw worn in the mall. Your budget will thank you for not paying as much money to learn your styles and sizes as you would in Macy's. Hair: Check out Paula Young's wesite for reasonably priced synthetic wigs, if your hair doesn't suit.
Shoes: Start with flats or quite low heels. No use buying 6 inch heels your collegemates aren't wearing to class.
If/when you decide to hit a local night spot, try to get a couple of classmates (bio-girls) to go with you. They can run interference in the ladies room and help you with makeup and deportment. If that is too scary, go to a local crossdresser social/support group first and then go out with some of them.
Learn how to walk and how to sit like a woman before you go out. And I don't mean to wiggle your hips. Women glide, and men stride. So shorten your steps. Sit with your knees closed. Women don't sprawl.
And if there is more to it than visiting the other gender now and then, see a gender counselor. We have some listings at our links Medical area.
Hope that helps some.
Robyn