I too went to my first Xmas service...midnight Mass, if you can believe it. I thought, why not?
I too had a similar experience; I went to pretty little community Catholic church...just on a whim I stopped and went in. I sure didn't know what to expect but everybody was gracious and kind, I think they could tell I hadn't a clue what to do. The sermon was good, about helping others, and the adult choir was really nice. It was packed, and I liked seeing people of all sorts there together.
I especially liked "Peace be with you."