First Rosh Hashanah

[highlife]

So, I'm going to Rosh Hashanah dinner with my new girlfriend. It's not gonna be a big group, just her parents, sister, and one set of grandparents so not too intimidating. Also they are "progressive" so apparently not super religious.

I was born Protestant but consider myself agnostic. I definately respect most religions and take interest in them so theres not a problem there at all.

Basically I just want to know if there is anything cool I could do to "impress" them that I know a little bit about Judaism and respect it, without seeming like a total showoff/kiss up. Also is there anything I shouldn't do?

People have told me it would be good to say "Shana Tova Umetukah", or bring a few pomegranates. Good idea or no?