I know the OP said he just bought a big tent, so I'd recommend a folding cot for the grownups to sleep on. I have tried them all. Foam pad, Big Agnes inflatable pad, queen sized air mattress shared with wife, and XL cot. I listed them in increasing order of comfort.
If you hadn't already bought a tent, the most comfortable camping sleep I have found is an 11' camping hammock. (not an Eno, but a cottage vendor like Warbonnet Outdoors or Dutchware). These come with integrated bugnets. You are up off the ground so if it rains, water isn't trying to run through your tent. You can sit up and you're at sitting level getting out of your hammock, not lying on the ground which for me feels extremely vulnerable. Throw a tarp or rainfly over you if there is a chance of rain, or watch the stars if it's clear. No hotspots or pressure points from lying on the ground, a hammock will support you with equal pressure from your head to your feet. Watch some "shugemery" hammock videos on Youtube. Advice I would give would be, if you are hammocking in the summer in MS, spray your hammock with permethrin to keep mosquitos from biting you through the fabric as you sleep.
Depending on the season you are camping, you might consider a Thermacell or screenhouse as mentioned above.
Cookware, utensils, plates, drinks. A comfortable camp chair or bag chair to sit in. (if you have a hammock, this could double as your lounge chair during the day).
My kids have come up through scouts so I've spent a lot of time with them camping. You can bring whatever you think they'll want to play with, but they might just start playing with a stick. Or building a fort out of sticks and leaves. Who knows.