First thing is a tent!
You will need one with 2 bedrooms and a decent amount of living space you can stand up in. Some have bedrooms at one end, and look like tunnels, others have a bedroom at each end with living space and door in the middle. (See photos!)
Modern tents are ok to put up- but practice at home first!
Bedding: self inflating mattress are good and pretty comfortable, put layers of blankets underneath, to insulate the floor, then a sleeping bag with another blanket over the top.
Plastic storage boxes for food and cooking utensils. A couple of gas burners for cooking. A cool box, saucepans, plates, cutlery ect.
Table and chairs (folding) as it gets v uncomfortable doing everything on the floor!
Wellies/ crocs, quick drying waterproofs ( always best to be prepared in the uk!) a torch and battery lamp for nighttime.
Be prepared for the midnight rush to the loo (crocs and a torch!) or have a bucket with lid for the kids.
There are all sorts of camping gadgets you can get, but that depends on your budget!
Perhaps borrow one or go somewhere with ready erected tents for your first time?
We have had some great holidays camping!