I have a feeling you will be more prepared than even us veteran cruisers!!!
I've posted some tips before but I wil go over them again for any other newbies.
Bring an extension cord and power supply strip for extra outlets... there aren't many in the rooms.
Buy one of those airfreshner/night lights for the bathroom. Even rooms with verandahs get dark at night, and the bathrooms can smell. Not overly offensive, but still...
Get 2 way radio/walkie talkies that can be used on the ship and in the ports.
If you drink, get a soft sided rolling cooler and fill it up on the way to port. No ice!
Bring LOTS of sunscreen! It's expensive on the ship!
I have found my lanyard to be irreplaceable!!!
Bring pillowcases and different colored Sharpie markers. Drop it off at guest services and they will bring it back, signed by the characters!
Try not NOT MISS Palo!!!
Don't forget your daybag!
Don't plan a shroe excursion at every port. Take at least one port to just explore on your own.
Do not overpack! You will no matter what I say, but our family of three can do the whole week in just two normal sized suitcases. Don't even bother to pack denim since its really too casual. During the day, you are always in a swimming suit, and at night you dress for dinner. One pair of nice black slacks with different tops and one pair of black shoes will work. Then maybe a dress or two for the fancier nights. That is all you need!
And DO relax. I was so over planned my 1st trip that I spent the sail away party crying up on Deck 10 by myself! Its completely overwhelming when you get on the ship and probably takes a full day to get adjusted, so just try to relax!