As space is often expensive, being space and time efficient in gardening is often important. Urban gardeners will like to do edible landscaping, vertical, and even maybe square foot gardening. Layer type gardening and composting may save you time as well as resources. If you are short on space, consider share cropping with someone having the space. Some folks having the space may not have the time to garden (like me). For higher yields, some folks like to use green houses or hydroponics. Look forward to adding more here too.
Small animals such as poultry and rabbits are likely to be less expensive to raise. If you like fish, you may prefer to raise edible fish in your fish tank or even have a fish farm. In more rural areas, with more space, the options get bigger of course. I have seen where even buffalo were raised. For beginners it may be better to start with smaller animals like goats, pigs, cattle and more common livestock.
Hunting and Fishing
Every country has its own laws regarding this, so it may depend more on your interests or costs in what you can do here to save money. As meat seems to be one of the highest cost food in grocery stores, saving possibilities are good here.
As seasons are often limiting growing food and hunting, this brings on the need for preserving of course. Also, When you have a good deal on food, it is really nice to stock up and preserve for a later date. Canning and drying can be time consuming but is a great way to preserve food for long term storage. Freezing is less time consuming but does require very mild energy cost to maintain.
Obviously, the do it your self will save you money here as prepared food in the store or restaurants have additional expenses incurred. Some methods of cooking can also save you money. In the old days wood cook stoves in the forest regions saved on energy bills in multiple ways. My wood cook stove is also plumbed with a water jacket to heat hot water and saves on hot water bill. Also while cooking in the winter it serves to heat the home too which saves on home heating bills for many folks. In summer or warmer climates, solar cooking is great in harnessing free power from the sun.