Just did camping with my 7&9yo.
•Mats for under air beds. They get so cold at night.
•Layers. Layers layers. I went early august, it was warm, I slept in joggers, top cardigan and jumper.
•Flip flops/crocs for showers. Veruca central in there.
•Going for a week? Pack clothes for 2 weeks. Especially for the kids. They fall, wet themselves, fall again. Find a puddle. They go fucking feral. If there is mud in a 10mile radius, they are in it.
•Socks, so many socks.
•Night wees. Boys - wild wee on the grass. Seriously, just let them.
Girls - I still have a travel potty and I've used it at 3am.
•Bottled water.
•wine
•sleeping bags. Zip them in. They will freeze with a duvet.
•pillows - it's just not worth the neck ache.
•camp kitchen - plastic tub. Camp stove, gas, plates, cutlery, bin bags (so many bin bags), mugs, plastic beakers, kitchen roll, sponge dish soap dish towel. Wooden spoon, frying pan, chopping board etc etc.
•chairs - Halfords do them for £10, might be 2for£15 now can't remember.
•foldable table. Big enough to prep on and eat on.
•Wine
•toys - bat abs ball, frizbe, etc.
•solar lights that stick in the ground - Poundland for these.
•headlamps - I got them from millets on sale. These are a godsend. Kids love them and actually wear them.
•first aid kit. Plasters, calpol.
•Wine
Depending on where you can are shop closer and way home from any day trips.
But if you're taking a cool bag. Freeze a bottle of water (2L) and it takes ages to defrost will keep milk and food cold for a day or so.
Good luck. Camping is so much fun.
Take Wine.