Where are you at?
IF there is some kind of waterfowl production area near you.
You can just go and find someplace to sit in the weeds well before sun up and wait for the action to begin. Most, all ducks and geese take off at first light and go feed. If the wind is blowing hard It keeps the ducks moving, try to let them get past you and shoot going away . It is a lot easier to penetrate their feathers.
12 gauge? You ave to use steel shot for ducks and geese, anything smaller than a 12 you almost always need to use other Nontox shot in order to get enough shot density to consistently kill ducks, 12 is the easiest and cheapest route to go.
2 3/4 inch "Duckloads" are usually anemic at best. Pass shooting I would use #2, 3" and a full choke. You have to practice and pattern your gun, 40 yards is about max. If you don't have a dog or boat or some other way to retrieve your ducks only shoot them so they land on the ground. Jump shooting is fun too if you have a creek or a canal that you can walk.