There's plenty of ripe damsons and bullaces around here, worth keeping an eye out and you might also find some wild plums, crab apples, 'wildling' apples etc. I'd also be keeping an eye out for chanterelles, ceps and other wild fungi I am certain I can recognise, if you're unsure then don't eat but worth trying to identify them. It might be a bit early but you might find some feral hops, certainly in your neck of the woods.