I usually have a reasonable store of things at home, so was not planning on buying anything extra. If you don't, I can tell you what I have if that helps:
Rice, pasta, noodles, dried pulses, cans of cooked beans, tomatoes and coconut milk, a few sauces like a curry one and a pasta one for quick meals, herbs and spices, flour, dried milk ... basics I know I can use, but there is no point stocking up without a plan of what you want to do with it all.
If you like to cook, think about the ingredients you use a lot and get a couple of extras of each. If you don't tend to cook much, think about combinations you could use e.g. canned beans, canned tomatoes (and even canned cooked meat if you are short of freezer space) could make a chilli with a packet mix or your own herbs and spices stash if you have one.