I'm hanging out with this girl tomorrow. I'm scared?

This girl I like agreed to hangout with me tomorrow. Im worried about it because This is the first time and I really don't want it to be awkward! She said she is also bringing along a friend. What could I talk about with them? How could I make her feel comfortable? And mist of all, how could I show her that I really like her?? Help me out and please leave some tips.