your first step should be to lay everything out on the floor, and connect all the harnesses/swtiches that you got with your purchase.

from what it looks like on the auction page, there are the lights, then a harness that would go from the lights to the cabin, then a harness that goes from the engine bay harness to A) power and ground, B) some other plugs under the dash (probably for lighting the switches when the headlights are on) and C) the switches themselves.

now you should just have to find either a fuse in the under-dash fuseblock for foglights, or a harness plug that will work for them.