Welcome to Cruise-Chat!
We are so happy you have joined us. Lots of experience here among the membership, so you'll be getting some good information.
A first cruise is always exciting, and you have a year to wait for it. I like the western Caribbean. It is pleasant in December too, at least in my experience.
Our first Celebrity cruise happened to be on the Century, but that was several years ago and the ship has since undergone significant upgrading with many changes in the layout. Celebrity offers a fine cruise product. They are more reserved with very few announcements, and a more European feel to the service. I've always enjoyed Celebrity's food and service.
to see some reviews of the Century. Also note that you'll some good and not-so-good reviews. Don't dwell on the negatives. Some people read one or two bad reviews and they think they are going to have lousy cruise. I'd pay more attention to the reviews written by Tom Ogg. They are a couple years old but still mostly relevant.