Barb.. first off.. Welcome Aboard! Glad you decided to register and join in.
I've sailed the Triumph several times, and I have no doubt you'll have a great cruise. I wouldn't worry much about your accomodation. An upgrade isn't all that likely, with you booking a specific cabin. But I wouldn't worry.
You'll be too busy enjoying the ship and your first cruise.
The beds will just be two twins, moved together (if you like) to form a queen size bed.