Hi Cruise Mom,
First of all, let me welcome you to Cruisemates.
Let me see if I can help you.
Go on line to the Carnival web site. If you haven't registered, do so and if you have it, put your Booking number down.
They have a section on specialty cakes. Birthdays, Annv, etc. You can pick out the one you like. It can either be dilivered to your room, or in the dining room, and you can een pick out what night you would like it.
As far as gifts are concerned. In most cases, you can board a ship with wrapped gifts, but they might make you open them. What I have always done is take the gift, and the wrapping paper with me, and wrap it after I get on board.
You can also, in the section where you get the cakes, order gifts to be delivered to your stateroom either when you board, or on a day you would like it. They won't be wrapped, but will have a cruise theme.
My youngest son was 16 when he took his first cruise. He said it was the best gift he ever had. Anything else he received, was iccing on the cake, so to speak.
I am here to answer any of your questions. Let me know if I can help.