I wouldn't recommend feeding much if anything. Adding food to a pond which is probably loaded with debris, is low on water, and has no filtration may push it to toxicity. If it were me, I would not start by filling the pond with water. Rather I would clean it out. Get a large tub, put in some clean dechlorinated water then bail the water out of the pond with a bucket, if there are fish in the bucket pour them in the tub. As you expose them, remove debris and plants. You can put any plants you might want to keep in a separate container. When you get to the bottom, rinse until you get all the muck and debris out. Don't scrub just clean out debris. Then fill the pond with fresh dechlorinated water allow the water temperature to equilibrate then return the fish to the pond.