Food you grew yourself always tastes better, whether due to the freshness of the food or the satisfaction for growing your own meal. You will also save a good amount of money growing your own fruits and vegetables. Even if you live in an apartment, you can still plant in pots. Right now our winter garden at home has kale, romaine, spinach, broccoli and carrots.
2. Start composting
Not only is composting good for the planet, it's good for your garden. I have this compost bin (the ratings say it all..), which is crappy but serves its purpose. Really you don't even need an actual bin if you have a yard-- a pile in the corner with a tarp over it works just fine.
I collect kitchen scraps and mix them in a large compost bin with grass clippings, dead leaves, and rabbit and chicken manure. I do vermicompost (aka composting with worms) and it takes between three and six months for the worms to work their magic and turn your scraps into soil. I recommend Uncle Jim's Worm Farm for buying composting worms. You can order 1,000 live red wigglers for $25.
3. Ferment your own foods
Fermented foods are rich in vitamins and enzymes, and they work wonders for your digestion. Also, it's a great way to preserve food and it's cheap and easy! For fermenting veggies through lacto-fermentation, all you need is a jar and salt. Two of the easiest fermented foods to start with are sauerkraut and kombucha.
4. Get backyard chickens
Backyard chickens are the gateway farm animals. As the urban homesteading movement grows, more cities are revising ordinances around allowing backyard chickens. Look into your city's laws around keeping chickens-- most places allow at least two hens even if you have a small yard (roosters are another story). Aside from the obvious plus of having free eggs, if you choose to harvest your chickens you will have fresh meat and you'll know exactly how it was raised and prepared since you did it yourself. Further, chicken manure is excellent for your garden. Check out my How to Raise Chickens Part 1 & Part 2 if you are thinking about getting chicks.