Believe it or not, food actually DOES grow on trees!  I don't remember hearing anything about actually going out and picking fruit from trees to supplement ones diet.  You may be able to do this legally by asking an old person to pick their fruit for them in exchange for a little fruit for yourself.  Maybe if you're lucky and pick apples, you can return for some apple pie later.

There are also many edible plant leaves and flowers, such as Viola petals, Nasturtium leaves and flowers, mint, ornamental kale, etc.

Some listed:  https://whatscookingamerica.net/EdibleFlowers/EdibleFlowersMain.htm

In the woods you may find blackberries, wild strawberries, gooseberries, etc.

Just be sure you know what you are picking before you try and eat something.