I know many guys who never had a girlfriend at your age. They were still virgins in their mid-twenties and were really depressed because of this. What happens then is desperation, and it's like we women can sense it. In my experience, men contacting me (not a dating site, but close) have a tendency to say "Hello", "What are you doing" and then straight to "do you think I look good" or "Do you want to go out with me?" This puts me off and makes me reject people sooner because I "know" they're going to be like that. But back to the guys I know/knew. Even if they in their younger years never get a girlfriend, their first relationship seems to be deeper, lasts longer and is all that better.
In general:
Don't be desperate, we can smell it.
Take care of your personal hygiene and general looks (less gross foods = less fatty skin giving that "creeper" look sometimes)
Adopt a positivt look on life. I have done this myself, it's not as hard as I thought. I forced myself to be more happy and positive, and after a while it came easier and more natural 