A cook would not stock up on just any foods, nor would a cook buy quantities of things which would have a short shelf life. A cook might prepare for emergencies with the basics. Basics vary with differing tastes, he likes rice, she likes pasta, they all like potatoes and rare is the hater of tomatoes. Add in beans, many varieties be they tinned or dried. To make any of this palatable is a palatte of seasoning. Salt, sugar, pepper, cinnamon, vanilla are a start. To make the simplest dish will require cooking oil or butter and possibly some vinegar.
The above list is of the basics: all these kept dry in containers will last a fair time and could provide a basic diet. Add to them some fresh ingredients, flesh, fowl or fish if you are an omnivore. Or vegetables, herbs and fruit be you vegetarian or vegan. Follow recipes if a novice or improvise from experience.
Of great importance is enjoyment, somewhat difficult if you are unused to solitary dining. Consider that you now have leisure, a new experience. All those foods in publications and on television, treat yourself with your attempts at them and when the world calms you may prove to be a talented host.