2 main touring clubs in the UK, Camping and Caravanning Club, and Caravan and Motorhome Club. The former gets more tents, and the latter more caravans and motorhomes, as the names suggest. You tend to get a few more Cali’s on the CCC sites. The pitch set ups and facilities are very similar, and to a similar reliable standard - never 5* but steady 3*/4*, and almost never 1*. There are small differences in booking / selecting pitches, with CAMC it’s first come first served (so a 1o’clock scramble), where CCC are allocated pitches and while you can’t say which one you want, you can ask for 2 units travelling together to pitch together (like 2 vans, or a van and a tent. If you have a disability you can request to be close to the facilities with both clubs. CCC markets itself as “The Friendly Club” and to be honest there’s an element of truth there, from our experience.
Both the main clubs have Certified Locations and Affiliated Sites, which are privately owned and run, but you can book through the club, or get a rate discount. Then there’s the fully private sites, which can range from basic backpacker sites and sites without facilities, through ones with 5* facilities. Finally there‘s a growing number of stopover locations based around pubs, which tend to offer limited facilities, but at a low nightly cost if you also use the pub for drinks and /or food.
I‘d recommend anyone new to camping to try one of the main club sites, and also try a couple of private ones to see which style of camping suits you.