One of the skills you need to have in order to survive in nature is hunting. If you have an hunting rifle that makes things easier but if you don't here few ways you can hunt with traps that you can build yourself:
Pipe trap:
You need to find a thick pipe so a squirrel size animal can get into it 6 inch diameter is enough and about 34 inch length, once you got the pipe cover one end with a wire mesh if you have or with few short ropes, what we need is to light to get in but we don't want the animal to go through. Use duct tape to make sure it’s tight.
Fill the pipe with several handfuls of corn or bird seeds so it will attract the animal and hang it upright on a tree with some rope with the open end on top, make sure to check every couple of hours to see if you caught something.
Arapuca trap:
This trap is a bit more advanced and made for bigger animal like rabbits fox or even a coyote. You start by making a box (bigger the box means bigger the catch) wood box is the best option but a cardboard box will do fine just make sure you reinforce the cardboard box with some wood around it (so it will be heavier).
One you got a box you need 2 long thin sticks 1 normal size stick and 1 Y shaped stick.
Cut a notch on one side of the Y stick just below the Y with the knife and flatten the end of the other 3 sticks, put the Y stick in the front of the trap with the notch you cut facing outwards. Insert the flat normal size stick in the notch you cut so it will support it (don't let go of the stick so the trap won't close). Take the other two long thin sticks and put them between the back corners of the trap to base of the Y stick so it will support it (see picture) now you can let go and the trap won't close.
Put the food in the middle of the trap and when an animal come to eat it will touch the support stick and the trap will close over it.
You can put few traps around your shelter and then check them every couple of hours. Beware of putting the trap too close because you might attract the wrong animals to you camp.