I you want a girl all you have to do is enter a relationship or get really drunk do some dirty dancing. It may take a couple of trys but in a few months you'll have a girl of your own. It may be a boy so you may have to try a few times. Congratulations you'll then be a parent of a little girl and maybe a boy or two if they came first.
Alternatively you could wait another 10 years until robotics made enough progress to create the perfect human-like girlbotfriend for a small fee and free shipping. :D
I will agree with kameyia and anime kid. You just want to be your self, talk to the girl you crush on normally. Any dumb pick up line can make her lose interest in you.
My bad lol