The only predators I have are foxes and rats.
The coop will be behind a shed right next to tree which is up against a fence so it is quite sheltered, the run will be completely roofed so water and food will stay out in the run.
so if I made it out of pallets do I need to fill all of the holes with wood?
For that location, I think pallets for the sides would be enough weather protection, with hardware cloth to keep out the rats. Of course you'll need a waterproof roof--but that could be a piece of wood, or a pallet with hardware cloth (because of rats) and then tarp (because of water.) Or any other combination of materials that will keep out both the rain and the predators.