Hi Susan-Marie. Enjoy yourself - I just loved singing and playing in folk bands. These have been the most satisfying musical times, but best of all, I have been fortunate enough that these people have become my best friends over the years, and we've shared weddings, births and deaths during that time.
There are lots of musical arrangements for Irish music on the Web and I'd be surprised if your new group couldn't find a few pieces that were a quick fit. The site that immediately comes to mind is Barry Taylor's excellent collection of Celtic Midis. You can use NoteWorthy Composer (or similar) to print the music for each instrument in the arrangement ....but I suspect that this is probably a bit further down the road in your new relationship.
Break a leg.
Regards
John