What do you do if you were never taught how to talk to girls?

I'm at least smart enough to understand that girls don't want to be randomly approached, and they don't want to deal with guys that don't know what they're doing. I get that, but what am I supposed to do then? I don't want to be that guy that's obnoxious and persistent. And I don't want to make anyone uncomfortable by approaching them. I just get shut down for trying though. It just feels awful to talk to girls.
What do you do if you were never taught how to talk to girls?
Post Opinion