One good way for people in apartments to start some sustainable living is regrowing veg whenever you can. I don't necessarily mean container gardens/etc, but using veggies from the store to grow new ones in water trays left on the windowsill. There's lots of guides online!

Keep in mind that this is in your house and can't be affected by any right-to-garden laws, but I have heard of certain brand name veggie companies wanting to make it illegal. :) What they tend to do is trim off all that root fiber to make the veg "prettier" and thusly it can't regrow. Or they deliberately make sterile crop, but that's a whole other bucket of worms. Pick your veg wisely, especially from a farmer's market if you can!