Ah good stuff. Don’t go buying loads of stuff if you’re not sure whether you need it or not. It all adds up weight-wise and before you know it that bag will suck to carry. Like someone else said, hit a local camp site and see how you go - you can always go home if it all goes wrong.
And don’t forgot, legally you cannot wild camp in England and Wales whereas most of Scotland is fine except around Loch Lomond if I recall correctly.