You can plant an herb garden in a sunny window.
(pay close attention to their water, as they small pots tend to dry out quickly if in full sun).
How about a pallet garden on a patio or in a small area? (This one is made from two used pallets and weed cloth tacked to the bottom to hold the soil. It can also be made with one pallet and stood vertically against a wall.
Are gophers a problem? Use a half wine barrel or barrels to plant a vegetable garden or a dwarf fruit tree.
To make the barrel last longer, prop it up on bricks so that it has adequate air circulation below it.
Other examples of simple gardens I’ve run across.