Plated for sure. It doesn't deform as badly as plain lead and therefor flies straighter. As far as shot size, you should definitely pattern your gun to see which shot size it "likes" the best. In other words, which one gives you your best shot pattern in the "kill zone" (head and neck area). Also, patterning will help you decide which brand name of shot-shell and wad style your shotgun "likes" best. I , personally, like #5's because of penetration,but, that's just me
. I also shoot flite-control wads through non-vented choke tubes and they pattern great in my guns. But again, that's me
. You will have to get one of your parents, grandparents or good adult friends to help you sort through some of your choices at the range. Each hunter has decided what they and their guns prefer through experimentation as well as experience. Don't forget to pattern your gun at the different ranges you mentioned. I use a 1/8 inch thick peel and stick 12" X 12" vinyl floor tile behind my target paper to check penetration at longer ranges. You can get them cheap when they are on sale at the big home improvement stores, you only need a few. Hope this will help you.