With you being in Mortheastern Mississippi, you conditions are not much different from those here in East Tennessee.
For a pond to do best, it needs to be placed so that it gets atleast 6 hours of direct sunlight a day minimum.
Placing the pond a minimum of 15 feet from trees will increase the ease at which it is dug and reduce cleanup of leaves from the pond.
Ponds do best being a minimum of 3 feet deep.
Water that deep does not change temperature fast, which is better for the fish.
Depending on size, it is best to start out with singletailed comet
goldfish.
They need a minimum of 50 gallons of water per fish once they are full grown.