Coolage is right if you do meet up organize with a friend 1st and tell him to call you at around the time your supposed to met her so if you are meant to meet her at 1:00pm get your friend to call at 1:15PM. So if she’s an ugly b***h you can just say "OMG WHAT HES IN HOSPITAL IL BE RIGHT THERE" and get out of there without hurting any feelings.
As for the call JUSTR CALL HER it may be hard but believe that the second you say hello you will start talking about something but its true that’s how it happens. If you want to rehearse everything how are you going to talk to a girl you meet face to face in real life. But because im a good guy ill give you a little intro say:
You: Hey How are you (her name) this is (your name), (your friends name) gave me your number.
Her: Oh I was wandering when you would call.
You: I been busy lately
Her: Doing what?
From here you could do many things that will lead to convo. Throw in some mysterious and c&f make sure the call is short 5 min max and organize to hookup for coffee or whatever when YOUR free. That’s it