Don't buy branded "survival" food. Shit is a waste of money. But rice and oats and keep them as dry as possible. Dehydrated meat is usually pretty disgusting, so if you need to add protein to your diet, I'd recommend canned fish, specifically sardines and anchovies. Some people find that disgusting, but they usually come packed in oil, which you can save and use to other dishes. Dried cheese powder is another good thing to have, it is pretty shelf stable. Just don't buy things branded as survival food.