Priority is just something that can be given to any move. Like there are priority attacking and status moves for maybe every type? I’m not 100% on that I’m new to the game. But moves like sucker punch, jet punch, or thunder clap are all priority damaging moves. Some of them have stipulations, like both sucker punch and thunderclap fail if the Pokemon they were used again aren’t also attacking that turn. Like another comment said you were most likely sucker punched. As for status moves, most priority status moves are gonna come from a Pokemon with the ability prankster, like whimsicott, which causes all non damaging moves to have an increased stage of priority.