My recommendations:
Warburtons GF Tiger Loaf and the Farmhouse Loaf are very good.
Schar chocolate fingers, pretzels and maltesers (called Delishios) are great. They’ve just brought out mini-cheddars as well. McVities GF HobNobs are as good as the real thing.
Juvela White Mix is the only gluten free flour I’ve found works for baking cakes. It’s available on prescription or on eBay and Amazon. Expensive but it works.
Rummo gf pasta is the best, Sainsbury’s a close second.
All Sainsbury’s sausages are GF. Bird’s Eye do GF fish fingers. Hash browns and potato waffles are GF. Read the back of oven chips packets, though, as they often have a coating these days.
Standard meat or fish, potatoes, two veg are dead easy. Bisto Best gravy is gf.
Rice is gluten free - I often have a stir fry, with gf soy sauce, lazy ginger, chilli and garlic and sesame oil, whatever protein I fancy and a packet of Tilda brown microwave rice.
Baked potatoes, baked beans, cheese, eggs, shakshuka, fajitas (Warburtons do gf wraps), risottos, chilli, casseroles - all gf as long as you check your stock cubes.
It’ll become second nature, OP. Good luck.