Hi Joe,
As a fellow East ~Anglian I'll second Stew. I fucked over properly the first year that I played. Dead branches in long grass trapping my feet each time. You'll find the CQB in Snetterton has a good(ish) flat(ish) clear surface.
I'll echo Stew (again!) and say keep it light. My skirmish rig is belt, pistol holster, 1 x fastmag pouch, one deep .308 ammo pouch for spare BBs/speedloader/grenades/spare or empty mag, 1 x 500ml water bottle. The rest of my kit (gas/sarnies/big bag of 'just in case' BBs, big bottle of water, poncho, etc) gets dumped at re-spawn in a rucksack.
Polymer MP5 or similar lightweight rif and you're good to go. You don't need a load of load carrying gear as I learned the hard way when I started. Playing with all your kit on ones person led to a Skorpion/kit bag full of cheese and onion pasty... 😅
I play with arthritis as does my regular airsoft buddy. When our hips play up we lumber about like a pair of dinosaurs. We still enjoy ourselves. Some days all I can do is hide in a likely spot and wait for the enemy to turn up before blatting a load in the back.
Good luck with your first few games. What's your local site?