For self defense study what the Vietcong used for traps and tactics, Those fuckers were relentless.
For equipment don't pack one thing that does one thing, Pack one thing that does three or more things.
Learn to live with nothing and chances are you'll live with everything.
And like people have already said learn to forage for local wild edibles and learn to make traps and snares, You'll need to set more than one trap or snare to catch food as well and you'll have to check on em. A trick I like to use for my snares is you make one full loop (so it looks like and O instead of a C> ) on a small dry pine twig then twist the bottom so everything's tight, then break the twig to get your loop out and use that. What happens is when the snare is set off the loop tightens down on itself and holds the animal in place better.
Learn stone age weaponry as well, Worse comes to worse if all you have is a knife you should be able to make a bow or atlatl. I find traps and snares are easier personally but with practice you can make some really decent bows, slings, ect.
Outside of that learn homesteading, Survival is just that, Learn to live and thrive in a bad environment. Tribes that tended to farm have done better in history than hunter gatherers.
Al