You’ll have a great time. Celebrity is a bit more “refined” than Royal Caribbean (our other favorite line. Plenty to do. Lots of new people to meet of all ages. We like the more relaxed feel of Celebrity when when we aren’t traveling with family. RCL is a bit more family fun time oriented, which is nice too.
One suggestion I’d make is to find the message boards specific to your cruise. Both here and on “the other” social media site. It’s a great way to meet some folks who will be on your cruise even before you board. Sometimes little gathering or events are pre planned that make meeting new folks fun.
Enjoy you cruise. After the first one, it will become your favorite thing to do.