Dan, if you plan to go for car camping in the beginning, you don't need so much special stuff for the first time.
You just can take a few blankets, a pot of round about 1 litre volume without plastic handles, a cutlery kit from your kitchen, a few candles, a torch, a saw that is made for wood, a metal mug or even a solid ceramic cup, a few bottles with mineral water from the super market, and so on.
Special outdoor clothing are very nice if you are out in the field with a rucksack, because they usually are drying faster than Jean's or other cotton clothing. But if you have some spare clothing it doesn't really matter, what you take with you.
Your civil clothing are OK for the beginning, just bring everything twice with you!
(And take old clothing, off course)
Special outdoor equipment is mainly relatively strong but relatively light constructed. But if you just go the first time by car to one of the legal places in the list, it would be far better, to go immediatly in your attic, Kitchen and basement and to look for some stuff there, than going through hundreds of pages in the internet.
The only special thing you need is a cheap double wall tent. That is secure enough, that you can just use civil stuff from your house inside of it.
Take a barbecue grill with you and 3 bricks, make a fire under the grill and between the bricks and just put the pot on top and it's fine.
Take some bread and cheese with you, perhaps you can't manage to get the fire started...
And like this you can collect the first own experiences in camping during this autumn.
During the winter we can help you to choose a nice hiking equipment for the next spring and summer time.
Perhaps you should open another thread here in the forum where you ask for a cheap but good car camping tent for britisch 3 seasons conditions.