LIke others have said, each NYS campground is different. Most NYS campground reservations are made through Reserveamerica.com. Many offer electric at 20 or 30 amps, but it is hit or miss which ones.
I do know Wildwood State Park on Long Island does have full hookups, electric, water & sewer. It's a nice park right on the Long Island Sound, but I live on Long Island and do not want to camp on Long Island. We prefer mountains, rocks & fresh water over the sand & saltwater on Long Island, so we head up north to the Catskills & Adirondacks for our camping trips.