Once you cook regularly, "figuring out what to cook and then searching for ingredients at various sections of the store" takes next to no time. Most of what you buy are the regular weekly standards. Just spent two minutes writing a shopping list before you leave home.

Then for the first few days after you shop, cook the meals you planned. And towards the end of the week, open the fridge/cupboard and think "what needs to be used up?"

The more you do it, the easier it gets.