How to respond to "need some new people to talk to"?

There’s this girl in my English class who I’ve never talked to but she’s friends with the girl I like (not that I’d use her, I just think I should be friends with more of her friends). She keeps posting “need some new people to talk to. hmu” on facebook and I wanna get to know her, but there have been plenty of awkward and short-lived failed conversations that begin with just “Hi” and I know that would probably be most of your advice “Just say hi!”. But what’s after that?