Vector3 Expected but got number, need help on my custom movement! How do I fix it?

This is just testing. Everytime I play it says Vector3 Expected got number

self.Update = function(position)
		--Forward
		local Position = Vector3.new(0,0,0)
		self.UpdatePosition = Position;
		
		if self.forward == true then
			Position = Position + self.Forward * Speed
		else
			return;
		end
		--Backwards
		
		if self.backward == true then
			Position = Position - self.Forward * Speed
		else
			return;
		end
		--left
		
		if self.left == true then
			Position = Position + self.Sideways * Speed
		else
			return;
		end
		--Right
		
		if self.right == true then
			Position = (Position - self.Sideways * Speed)
		else
			return;
		end
	end