Bedding: Alexzander could sleep on a folded up doona or an inflatable matress depending on how much room you have or even a camp stretcher

Nappies: if it is a proper camp grounds bins are provided.. otherwise take nappy sacks and dispose them when you get home,

Clothing. Personally I would take 1 set per day plus 2 spares for the entire time. Jammies.. take 3 pairs and if there is a pool maybe 2 sets of swimmers

insect spray, hats suncream and shoes.. and a small amount of washing powder (and coins) incase you need to do washing

Have Fun