I have found that M&S do a nice birthday cake you have to order it but costs 20.00 so it’s not over priced and they also do a range of cakes and pastries, breads and a fridge range as well so a few nice treats. Ocada do a great range and Tesco has a quite a few choices as well in the designated areas now as before the choices were so small! You can a lot of nice recepie online from doves farm and the flour is on sale in Tesco as well as sainsburys.sponge and pancake kits are nice at Tesco g/f shelf. Most home cooked meals are already g/f and Tesco do a gravy granules cheaper than bistro g/f one and you can get some cereals in lidal as well!!
Be careful on hidden gluten so stick to things with cornflour and no malt vinigar s only other types as malt is not suitable for us ceoliac either ! I have 8 years now and it’s much easier as you go along and also more choices now as well but I get gluten free pastry rolls at Tesco and make sausage rolls and jam tarts and I make meringes and pies so you can do party food ! Pizza bases you can buy as well and do toppings or g/f pizzas in the supermarkets are not bad and they have Allsorts it bits now and chicken bits as well for party type meals !!
Waitrose and morrisons too as all got different tunings and the home kits on scones are nice in the co op!!