Oh Boy will you have fun. First cruise is very exciting, Your first look at the ship live will take your breath away. I cruised the Glory my last time out. Very nice, the ship theme is colors, Blue longe, Golden and platinum dining room etc. My daughter danced on this ship. She is now on the Liberty.
So what to do... If your children are young be sure they take advantage of Camp Carnival, it isn't just taking your kids off your hands so you can have fun. They get to go back stage and meet with the dancers and have special stuff they do. If they are in the teens then there is another group for them. Use these. There are 2 formal nights. How often do you get to dress up to the nines and have an elegant night? Do it, bring your formal wear, or rent it on the ship. Get a formal picture of the family. Use the spa, go to the talks about shore excursions, they will tell you all about them so you can find what you want to do. I suggest staying with the Ships Excursions they are safer and you will be guarenteed to get back before sailing time. Use the room service, the food is free, tip as you would a delivery at home. Go to the shows, especially the big production numbers. Glory Days is great. Sample the fish and chips, best I have ever had. If you want a quiet place to just mellow, try the side decks, not much activity there and you can just watch the sea and feel the stress flow away.