It isn't always better for the environment to buy food locally. How it was farmed and how it was imported matter too. Most of the carbon footprint of groceries is from how they were grown and not how they were transported.
If it's in season where you live, then locally grown is best. If it's out of season, you need to consider a more nuanced point of view.
some surprising sustainability
* Growing almonds for almond milk damages ecosystems and uses a *lot* of water. 80% of the world's almonds come from California, where severe droughts can be a problem
* Soy farming drives deforestation in South America. Tofu can have twice the carbon footprint of chicken
* Fish populations are dynamic. Sustainable fishing leaves land open for reforestation
* Bioplastics are not necessarily better than recyclable plastics like PET
* Industrial cooking is more efficient than home cooking. Tinned tomatoes, chick peas, etc can be a good option
* Cling film is plastic, and plastic is not good. But if you use it carefully, you can prevent food waste, which is worse. Beeswax wrapping is ideal
* Leather can last over a decade, and is biodegradable. Fake leather is made from short lived plastic
* Cotton production is energy intensive. A cotton bag needs to be used 149 times to be more carbon efficient than plastic. Get a good one. Use it often
Sunbeam City is a Libertarian Socialist solarpunk instance. It is ran democratically by a cooperative of like-minded individuals.