The secret, for all you single, dateless, fretting young guys, is to practice talking to girls. Have conversations about simple stuff: news, school, homework, what they are wearing, weather, whatever. Just talk to them. Talk to as many as possible. Don't worry if they are pretty, slim, fat, big busted or plain. It's just practice and quantity is important at this stage. Keep the talk short and smile at them. Try not to stare at their breasts if they are wearing skimpy tops. I know that can be hard, but try.
Repeat repeat repeat. Everyday. Two sentences may be enough if you have them with 5-10 different girls a day. Always be polite, look them in the eye and smile when you leave. You can even say "thanks".
It's alright to talk to the same girl more than once in a week. That's kinda the point after all. You may find that after a few weeks of this, some of the girls will come find you.

It's hard work, but you can do it. You'll be a new person within 30 days.