It's hard to find bread in some places right now, so it makes sense to make your own. Flour seems a little easier to come by and you can use white or whole wheat, spelt or other wheat types of flour to make loaf bread.
There are ways to make gluten free bread with other grain flours but you'll have to go looking for recipes there because I have never made that.
However, if you're short of wheat type of flour or want to stretch what you have, you can substitute a fourth to a third of other grain flour and still make a decent loaf of "light bread." Oat flour, rice flour and barley flour are commonly used. Be aware that they will impart a slightly different flavor to your bread.
No sugar? No milk? No oil? No problem. Bread: Frugal Staff of Life shows you what to substitute and how to do it. And if you don't have yeast, you can get sourdough started. Making sourdough bread is pretty much the same as making yeast bread, it just takes a little longer to raise.
Even if the shelves are empty you can still have bread - and better bread than you can buy anyway!