Not all those who wander are lost, but I certainly am!
Having lived in England for two years I can definitely say that British slang is regional. I lived down in Kent, so there was probably a fair few Northumbrian Britishisms that I didn’t get to hear for having not visited. These are a few of the ones I heard, and that earned either a look of confusion or a touch of horror on my part. Learn from my confusion and listen for these when you visit England next!