how do people get a girlfriend or boyfriend even whatever?

Okay, I have never asked a single girl out in my life, they pretty much started ask me go do something all that. But, I really like to chilling with my friends who are boys, but we are not gay at all. A lot of them already have a girlfriend in their life, which something I don't have. So, one of them told me to get a decent car audio system to playing loud around girls, which I did but that did not get me a girl friend at all. Now, I am just going to sale my systems. But how to start to ask girls out all that, which what I am interested or the starting point.