Take it from someone whose helped out my bros in college.
You have to fall down and learn to pick yourself up. You can't learn how to socialize if you don't go out there and make an effort.
Go out and do something where there's a lot of people. Like a county fair or a concert or some kind of social mixer. Be at ease and don't try to be eager to please anyone.
Besides making sure you're dressed appropriately (don't be a slob. At least make some effort in ironing your shirts and pants, have proper grooming and bathing, brush your teeth and have a mint), enjoy yourself. Make eye contact, crack a joke, or laugh. Stand up straight and don't get overtly excited.
When you meet new people, listen first and then talk. Identify the type of people you're encountering, be tactful yet witty when responding to them, find a common interest to talk about, and remember have fun. You're meeting new people and they're meeting you.
And if it fails, so what? You'll never see those people again and you learn from it. Move on and do it better next time.
I wasn't a stud muffin in college, but girls liked me because I could take a joke and had a shit-eating grin whenever I turned it back on some uppity bitch. I've been slapped in the face a couple of times and I replied, "Damn girl, you're moving onto some kinky shit. But I liked getting slapped in the ass" Girls like a guy whose confident and knows how to have a good time, hence how I got numbers here and there. You have to develop positive qualities that makes a girl seem interested in you.