Most Helpful Girl
First thing I would do is think about the fact that you are both just people, don;t get intimidated by her and try to be yourself. Talk about a show you saw last night, does she like movies or shows or a certain kind of music? maybe you can recommend something to her. Sometimes conversation will just flow naturally, if it does just go witrh it. Make sure you're not doing all the talking though, and asking questions always helps... don't interrogate about her life though lol good luck!
Most Helpful Guy
If you two don't automatically converse then maybe consider another girl?
Hey I might go out for lunch this week with my crush who I've liked for 9 months too.
Okay, if you're really out of ideas:
Ask her to tell you a story. Ask her to ask you questions. Ask her what she wants to talk about. Ask her what's on her mind; ask her what she's thinking about. Ask her about herself. Ask her about her opinion on something. Ask her about anything about her, because girls love to talk about themselves, and it's nice to show that you care about what she says and thinks.
Maybe if it's silent at the very beginning, say "so, what is happening in the life of [her name]."