How do I get a girlfriend?

I've always felt like I'm missing something in my life and I think that I'm missing a soul mate or something. I haven't had a girlfriend since 6th grade and I'm in 10th. I don't know why I haven't had one since. I'm kind of a shy person at first and when you really get to know me I'm totality different. I think I'm judged as a really shy person and that makes people not want to have anything to do with me. I'm pretty much desperate at this point.