How would I make a script that finds the first child with a certain classname?

So what I want to do is make a script that gets a player when they enter the game and destroys there hat

game.Players.PlayerAdded:connect(function(Player)
    Player.CharacterAdded:connect(function(Character)
    end
end

That is what I have so far but I don't know what I would do to get the hat and destroy it.