#1 Let her know you’re interested in her. Talking to a girl isn’t as simple as walking up to just about any girl and asking her out on a date. It may work in the movies, but in all probability, it won’t work in real life. A girl needs to know you’re interested in her so she can evaluate you.
If you just walk up to a girl who doesn’t have a hint that you’re approaching her, you may just end up shocking her. And she’s going to say the first thing her mum taught her to say to intruding boys. “Go away!”