It's many a long year since I've been camping but (since your post assumes basic facilities, with no refrigeration available and no shops to buy fresh food from), it has to come down largely to tinned or dried products.
I actually quite like some of the 'Vesta' range. (Yes, I know that they're rubbish really but I've usually got some at home as 'comfort food'!). They're easy to prepare at a campsite and (for me) quite tasty. (The instructions include melting a *** of butter in a frying pan but that's easily replaced by some cooking oil).
Then it's down to canned stews, baked beans with sausages, etc. Such meals can be served simply with a few slices of bread. (While it would be nice to have some lovely fresh 'proper' bread, supermarket sliced loaves last far longer, so that's what I'd take with me).
Tea and coffee can be served with UHT milk (which keeps for a day or two after opening, even without refrigeration).
However, let's be honest here. If I was looking for a campsite these days (I'm 61) I'd want it to be very close to a pub anyway!