Might I suggest the various crowdsourced fruit maps be shared when you address Guerilla Gardening. They're not it per se, but do tend to go hand in hand. And will be helpful for the most vulnerable as they suffer from inflation and the other ills of this regime.
A number of cities nationwide should have free tree programs, and sometimes those include fruit trees. I'm only familiar with Los Angeles where we have:
https://lacity.gov/highlights/get-free-trees-planted-your-home-or-business
https://archive.is/oN9Eb (LA Times paywall busted sources for LA & Orange Counties)
Last I looked into it, LA's program really limited the number of fruit trees though, which is rather sad. I think it was one per household.
And here are a few links for grocery store fruits that can be tried for guerilla gardening. A lot of fruit trees - like citrus are grafted onto hardier root stocks, these are the bare root varieties you get at nurseries.
So there's no guarantee a store fruit will result in a good tree. But these are the best bets supposedly. https://brightside.me/articles/8-fruit-trees-you-can-grow-from-the-seeds-and-pits-of-your-own-fruit-498010/
https://www.bhg.com/gardening/vegetable/fruit/how-do-i-plant-seeds-from-grocery-store-apples/
A search will reveal many similar instructional articles for various fruits.
According to the US Department of Agriculture, all adults should eat about 1.5 to 2.5 cups of fruit daily. Although today it’s easy to buy all the products you need in a nearby supermarket, it’s still much healthier to grow the plants yourself.
DoomsdaysCW
Hippy Steve