Sourdough is very easy to make for yourself, and is a sensible lifestyle improvement you can make over buying store bought bread. There’s a rabbit hole you can go down with buying and storing shelf-stable whole grains and milling your own flour for maximal freshness and nutrition profile, but you can still get started with store bought flours and little else - a sourdough starter kit, salt, water, mixing bowls, and an oven to cook it in. Organic and non-gmo white flour isn’t that much more expensive than the bleached shit you probably have. You get into steeper costs when you start buying ryes and other more nutrient-dense grains. The sourdough starter itself is pretty much idiot-proof and can be relatively low-maintenance if you refrigerate it for most of the week. If you’re cooking for yourself a single sourdough boule may be all you need to supplement your diet with some low-glycemic impact carbs.
Sourdough (particularly rye) also has other benefits - if you make more than you need, then you can also use the leftovers to make kvass, a tasty beer-like probiotic drink that is supposedly comparable to kombucha in terms of digestive benefits. You can use some of the sourdough starter you’re already going to be culturing in place of commercial yeast for the fermentation, resulting in a very low-alcohol drink (like home-made kombucha, you’re looking at 1% ABV at most. Obviously that’s a fringe benefit if you enjoy beer but want to cut back on your alcohol intake. With just a few flavoring ingredients (hops, lemon peel, raisins, maybe a sprig of mint) you can produce something that tastes very similar to a beer. But you can also flavor it with just about anything and tailor it to your preferences. If you add beets to the jar, you’ll end up with a red kvsss you can use as an ingredient to make borscht.
None of these things are very time- or resource-intensive - you can get by with mason jars, bowls, and tea towels you probably already own (perhaps not quart and half-gallon/gallon-size mason jars, granted - but purchased easily enough online). Airlocks for the sourdough starter and kvass are nice to have and pretty cheap to buy once you know what you’re doing.