First time on Disney cruise… I know I need to register kids for the clubs if they want to go, but do I need to register them for specific activities? Looking at Stitch Space Goo and Pajama Pal Party… I don’t want to disappoint my kids if these activities will get full or if I have to register for them (since first time cruiser, I think return cruisers would register first?). Do kids register for specific activities? Do these activities fill up?