is there any way to assign a numerical value to math.random?

Creating the table

You can either store each position as a Vector3 value, or as a value that is easily converted to a Vector3.

For the sake of understanding, for now lets just put actual Vector3 values inside the table.

local Table = {
	Vector3.new(25, 0.5, -27) ,
	Vector3.new(25, 0.5, -4)
}

Selecting a random value in the table

We are going to use the relatively new Random datatype in order to get a new number. Consider this a small tutorial.

First we create a new Random object which contains a new state of randomness.

local state = Random.new()

Next, we call the NextInteger on our state, using 1 as our minimum, and the length of our array as our maximum. This will generate a new integer(whole number) within the range of indices on our array.

local randomIndex = state:NextInteger(1, #Table)

Lastly, to get the Vector3, we now index our table with the randomIndex, and it gives us the associated value.

local randomPosition = Table[randomIndex]

Boom! The variable randomPosition now contains a random position drawn from our table.

Teleporting the Character Model

Your current method of CFraming their Head is unneeded, and a bit overkill. Before joints were changed, that would decapitate a character.

Instead, you should use the MoveTo method on their character. This is very simple, and it takes a Vector3 as a single argument.

character:MoveTo(randomPosition)

Getting the Character Model

Instead of using a LocalScript, you should likely be using a Script located in ServerScriptService. The reason for this, is you want everyone to teleport at the same time, and handle it in a central location.

To get everyone's Characters, you should get a current table of all of the current Players, and then if their Character Model exists, teleport them, if not, they are dead or still joining and will have to wait until the next round.

local players = game:GetService("Players")

local function teleportAll(position)
	for _, player in pairs(players:GetPlayers()) do		-->iterate through all current players
		local character = player.Character			
		if character then						-->check if character exists
			character:MoveTo(position)			-->teleport to given position
		end
	end
end

Putting it all together

We have all the components now, let's put it all in one Script located in ServerScriptService and throw it in a while loop.

local players = game:GetService("Players")
local state = Random.new()

local Table = {
	Vector3.new(25, 0.5, -27),
	Vector3.new(25, 0.5, -4)
}

local function teleportAll()

	local index = state:NextInteger(1, #Table)	-->random index
	local position = Table[index]				-->random position

	for _, player in pairs(players:GetPlayers()) do
		local character = player.Character			
		if character then
			character:MoveTo(position)		-->actual teleporting
		end
	end
end

while true do
	wait(5)
	teleportAll(randomPosition)
end

The rest is up to you!

amanda