How would I fix this script that moves players to a specific area in the map?

First, fix the blatant style problems.

Use standard function declaration syntax:

function name()
	-- body
end

Tab your code, and put spaces around operators! It makes it easier to read! Remove clutter!

function MovePlayer(player)
	for p = 1, #Positions do
		player.Character.Torso.CFrame = Positions[p]
	end
-- FUNCTION MISSING END

Use generic for loops:

function MovePlayer(player)
	for _, position in ipairs(Positions) do
		player.Character.Torso.CFrame = position
	end
end

Use the standard events. There's a CharacterAdded event -- don't use Changed.

function PlayerEnter(player)
	-- Bunch of irrelevant functions here
	player.CharacterAdded:connect(MovePlayer)
end

Now, this should work. However, MovePlayer will essentially only care about the last thing in the list:

n = 5
n = 4
n = 9
n = 3

Does the same thing as simply

n = 3

Which is all the loop is doing. If you were to add a wait, you would see the player appear at each point, then move to the next.

I'm guessing you want to pick a random point from the list.

function MovePlayer(character)
	character:WaitForChild("Torso").CFrame =
		Positions[math.random(#Positions)]
end