Don't feel like you have to go all crazy! Just enjoy what you can! It'll be a blast no matter what! Get a taste and a feel for the cruise and next time to you can try to cross everything off a list!
TIPS:
-Bring your own tervis/mug: main deck floor has soda machine available 24 hrs, its nice to fill up before bed.
-Bring a pillow case or something to get signed by ALL the characters. You drop it off at front desk first day and I think its returned at the end. 2 things per stateroom (or per kid if +)
-Disney allows you to bring your own alcohol!!

So monopolize on that and pack some miniatures for those tervis drinks at night

-Room service doesn't cost extra and you can get a cake of the day and or mickey bars which is pretty awesome, although I never have enough room!
-Don't forget to bring door decor!! You can totally decorate your door as long as its magnetic! If you use stickers and it leaves residue you could be charged a clean up fee. But magnets are fun!
You'll see a lot of decorated rooms and FE's (fish extenders, with is kinda a gift/craft exchange) and there's plenty of threads about that! FE might be a bit much with young kids on your first cruise, but I wish I had done it my first few cruises. Took me a while to discover it.
-Also if your into it, don't forget you can get dressed for Pirate Night!! It's such a blast and I usually hit up Target after Halloween and you can usually find some Pirate things on clearance!
Just a few tips!! But you'll have a blast!
DCL is the best!!