Place your trap in an area where there's consistent pig activity in an area where you can stake it securely down. Leave your trap open (unset) for a week or 10 days while scattering bait around the area of, and in, the trap. If you're getting action, after a couple of days re bait and set the trap. For some reason pigs don't care about the blood in the trap and I've killed a ton of them inside the trap and drug them to the truck after they were dead.
For bait try feed corn in a plastic barrel covered in water. Add a few gallons of out of date whole milk and some yeast and let it stand in the sun for awhile (make sure you know what's down wind). An open panel in the top of your trap is a good idea because deer and turkey will often eat your bait too and if they trip the door they need a way to escape.