What is the most logical next event?

How to talk to a girl you don't know
Always look at a girl's face.
Never look at her body, she might think that you are a flirt. Also, eye contact is considered important when communicating in most western cultures.
Try to start with a " hello " or " hi " and a simple smile. If she smiles back at you, it means she is paying attention to you now, and wants to talk to you.