If you let us know the supermarket chain that you usually use and the sorts of things that you think you might have trouble finding (e.g. sausages) then I'm sure that someone can help you. (Supermarkets such as ASDA, Morrisons, Sainsburys, Tescos and Waitrose are all good choices as they usually have FreeFrom Sections. Aldi and Lidl do not normally have FreeFrom sections although Aldi do have some products that are useful like their own brand of "Pringles" that are GF).
If you join coeliac UK then their book contains lots and lots of products and is divided into categories such as baking and ASDA. Its great to use this book at least for the first year.
Do ask for help on eating out in a particular location and also which chains are better for GF. Also click on the supplementary board where older messages about venues etc are stored.
If you are thinking of holidays then Italy and Spain (including The Canaries) are pretty good for GF availability.