Hey, welcome! While I’m not a native, I’ve lived here for a few years now and would be happy to share some info!

I have to say I’ve been pleasantly surprised by the amount of vegetarian stuff you can buy in most supermarkets here. My go-to for just adding a meat replacement into a dish is any of the “Quorn” branded stuff. I will say though that normally it needs quite a bit of salt added to it. Especially the mince is great though if you want to do something like a stir-fry or burritos. Their cold-cut looking selection is also pretty decent (the vegetarian ham slices etc), I prefer the vegetarian over the vegan options though, I think they taste a bit better

Other than that, there is a brand called “Linda McCartney”, their stuff is pretty nice as well and on offer quite a lot.

I haven’t been to Aldi and Lidl in a while now, not sure if they have any off-brand/own-brand options that are decent but I think it’s worth a try. Anyway, welcome :)

And be careful when you’re in traffic, people here are terrible drivers

Edit: oh and I forgot to say about oat milk: you can get Oatly at Tesco, Sainsbury’s etc, there is also a nice brand called Minor Figures, they have it at Tesco and Lidl sometimes. Otherwise Asda (another cheap-ish supermarket chain) and Lidl have their own brand of barista-style oat milk, can’t remember the name off the top of my head but it’s easily as good as Oatly and much cheaper