Turn off the electricity at the main breaker to the entire house.
Run the wire through the hole that is cut for your light, and strip 1 inch off the electrical wire, and attach the wires to your security light, matching colors. Ground wire will always be screwed on to the green screw of the base of the fixture. Screw up your light.
Go to the nearest outlet and remove the faceplate from the outlet and unscrew the outlet. Run your wire in the wall to your outlet. Cut to length.
Strip 1 inch off the wire, and attach the wires to the side screws of the outlet by matching color.
Screw back the outlet, and faceplate. Turn on the electricity and test your work.