I am in the US so I don’t know much about the UK specifically, but generally speaking I would think about starting small and working your way up.

For example, in the US there are many state or national parks that offer campsites where you could rent a basic cabin so you don’t have to worry about a tent. Or you could get a site with a covered pavilion with tables and benches so you don’t have to worry about seating or shade. Many have built in charcoal grills and fire pits. I would also recommend you start with somewhere that has access to plumbing and maybe even electricity for your first few go rounds.

There are also privately owned parks that cater to the “glamping” crowd where you can have access to a fancier cabin and other amenities like swimming pools, sports equipment, etc.

As far as camping equipment I would highly recommend you start off buying used gear. Good equipment can be pricey because it is meant to last, and you are not even sure if this is something you’re going to stick with yet. Try out some used gear and see what you like and don’t like about it. If you decide to stick with this you can always invest in better gear later. The basics should include a sleeping bag, tent, and maybe a propane stove. There are many things you probably already have or can make do with something. For example you don’t need to go buy specialty camping cookware when you can just bring a pan and utensils from home. You don’t need a backpack unless you plan to do some actual backpacking; a trunk or duffel bag is fine if you’re driving into your site.

Anyway, hope this helps! Enjoy your journey!