Hi
I see that you live the other end of Wales from me, but the weather is the same most of the time.
Whenever I go out to camp, I like to go as light as possible, mainly because I don’t like to carry things I don’t need.
I never carry a tent, sleeping bag or sleeping mat purely because of bulk, although they are lightweight there are plenty of natural materials you can use.
What I usually carry will fit in a 30L daysack & my pockets.
This would be my normal kit :
A good knife (plenty to choose from including mine)
Gransfors Bruks wildlife hatchet (lightweight and an excellent tool)
Fire starting kit (firesteel & cotton wool or other tinder)
Army poncho (just in case I need a quick shelter)
Billy can (stuffed with as much kit as possible to save space)
Paracord (plenty of it)
Water bottle
Mug
Fork
This leaves me enough space for food to cook & teabags/coffee etc, plus a couple of extra items of clothing. Bearing in mind that you are already suitably dressed for the time of year.
Of course this is what I like to carry now, I used to carry a lot more until I found out I did not need it. It’s surprising how little you need to be comfortable in any weather at any time of the year.
My advice to you is not to rush out and buy lots of kit, but to have a go using what you already have , then deciding what else you need.
Good luck
Eifion