Welcome to the forum Cindy. I have never played in a band either, but agree with X4 that there will be a rehearsal, and if there isn't you should suggest it, or maybe approach someone in the band - maybe the pianist to have a run through of the songs. I think the drummer will not be a major distraction as she will be more in the background keeping the beat, probably.
You probably need to know if they expect you to play rhythm only or if they want you to solo at any point. Also maybe what amplification might be needed because one guitar unplugged probably wouldn't be heard in a band.
There will be other more experienced replies soon.
One good thing about music is that when it hits you, you feel no pain - Bob Marley