I think it would depend on whether you're travelling to the place you're camping at by car, as to what you take! If you are driving there...
-tent
-comfy rollmat/SIM/blow up mattress
-decent sleeping bag (trust me, it's hideous being cold at night, when you're camping! Also don't ever underestimate the weather!) +/- sleeping bag liners.
-suitable clothes (layers, waterproofs, beanie hat, warm socks)
-torch and batteries
-travel-john/she-wee
-toilet roll
-insect repellent spray and a basic first aid kit (with any usual meds, plus basic pain relief/antihistamine tablets etc).
-Icebox/coolbox: freeze some bottles of water before you go, put food in ice box, use frozen water bottles to keep food cool.
-cook set: small stove, saucepan, bowl, cup, plate, knife/fork/spoon, a flask (so that when you've boiled water, you can keep it in the flask), water bottle for drinking.
-something to wash up plates/cutlery.
-hand wipes/baby wipes, hand gel.
-camping stove*
-book/kindle/puzzle books/cards, in case weather's crap and you're stuck inside tent.
-snacks
-folding chair
*doesn't have to be expensive! I used the army issue hexi-burners (with hexiblocks) and mess tins for years, until I had kids and was therefore cooking for more people than just me. I now have a Cobb Pro and a multi-fuel Trangia (but that was after years of camping and trying different types of stove). Everyone's preferences are different though.
I guess you'd need to speak to the rest of the group and see if you'd be doing meals together, or expected to sort your own. Enjoy your time camping :D