In order to have food stored, it basically has to be packaged in plastic or glass. Peanut butter. Jelly. Bread.
A jar of peanut butter is the perfect food for someone without fridge or pantry. It can be stored at room temperature, it is calorie-dense, it is cheap, and it actually has some nutritional value.
If I am ever forced to live at poverty income without basic residential infrastructure, I would definitely walk to the nearest actual grocery store and carry back peanut butter. You can also keep eggs around a while, even in the US, if you can replace the cuticle (removed during processing) with wax. I'd probably cook them in their shells with an electric kettle, dip them in paraffin from plumbers' candles, and put them back into the container.