As far as learning enemy skills, as long as one person has the "Learning" ability equipped, you can learn an enemy move, so long as it doesn't disable your character (or at least in the case of wing scales, if your character gets confused, you won't learn it). As far as using the moves, each move requires you to have a specific piece of cat food, which you can get from upgrading one of the Fort Lune spots and buying from the Adventurer who saves for you, or by using the skill "Dig" which you learn at job level 4.