Congratulations on your upcoming wedding in Key West! You're going to have a wonderful time on Rhapsody, whether it's your first or 50th cruise. And the fact that it's your honeymoon will make it even more special.
Just remember that it's YOUR vacation. The ship offers a lot of things to do, including a get-together for honeymooners/newly married, and you can do as many or as few of the organized activities as you'd like. For a really romantic experience, take a few minutes to go out on deck late at night, stand at the rail with just the ocean in front of you, maybe the moon above. You'll feel like a million dollars!