I just met a new girl last night not sure i should...?

i met her and we added each other on facebook.. now what?.. should i wait and talk to her on chat (waiting for this has KO'ed me b4) im leaning more towards a PM.. what should i say in the PM (this is pretty much the main question) we talked about her starting college thats about it or all i can remember.. and is askin for a coffee in the 1st convo/PM a bad idea should i wait for the response.. facebook and dating is retarded shoulda just got her number.