How come I don't know how to talk to girls, approach them, and get to know them in a non-desperate manner? why?

How is every guy born with the ability to get a girlfriend or date without even trying? Do guys instinctively know this? It frustrates me and pisses me off because I have never had a girlfriend, still a virgin, and I am almost 21, I did not choose to be single this long. I believe the reason why I am still single is because I am trying too hard, I am appearing desperate or too needy, which I am unaware of. I seriously hate how girls are able to sense and smell desperation from guys so easily, I hate women's intuition with a pion. It frustrates me that girls even hate desperate guys despite the fact they have been single their whole lives, like me, seriously, how come every other guy is able to get a girlfriend or get a girl to date them without trying too hard, without being desperate, and why do I always do the oppossite of this? Is it the way my brain was formed? genetic? Seriously, being single my entire 20 and a half years of living is just enough already!!!!!!, I am sick and tired of being alone. It is hard for me to have confidence. Seriously, how does every guy get their first girlfriend so easily? because I know that the more girlfriends a guy has had, the easier they come to him.