unless you have a really really really long extension cord or the truck is stationary next to an outlet, yes, any lights on the truck will run off the battery, and you need to have 12V lights, not 120V house type - if you have no wiring, you should get a replacement wiring harness for your year, which will give you all the necessary connections
there are 12V Christmas [holiday?] lights that you could rig up on the truck, but if you just wanna have some yard-art, run an extension cord out and use normal outdoor house lights
Bill
