how do I make the textlabel change text based on the amount of players in the game?

got it, uh something about not being able to reference the property so instead needing to reference the object :D

To count players inside a Text Object you first want to get players that are in the game at the moment, you simply do this as I show you:

local players = game.Players:GetPlayers()

to count the players from the "players" variable you use a hashtag, you do this as shown in the following:

--script.Parent.Text --but your own text route here
script.Parent.Text = #players --"#players" is the current amount of players in the server

In order too continuously check for the current player amount in the server you will have to loop, the entire code would look like this

local players = game.Players:GetPlayers()

while true do --loop start
wait() --prevent exhausting
script.Parent.Text = #players
end

use this to your advantage.

The best way to do this is not through loops as many of the other replies would suggest.

First, start by getting the Players Service, since we will be using that, and defining your TextLabel. For example's sake, I'm just creating one - feel free to assign this variable to an already existing TextLabel

local Players = game:GetService("Players")

local TextLabel = Instance.new("TextLabel")

Now, initially assign the text the amount of players in game. Do this by making your code look like:

local Players = game:GetService("Players")

local TextLabel = Instance.new("TextLabel")

local NumberOfPlayers = #Players:GetPlayers()

NumberOfPlayers = tostring(NumberOfPlayers)

TextLabel.Text = NumberOfPlayers

All I am doing in this is getting the number of players (by calling the GetPlayers function which returns a table of how many players are in the server, and then getting the amount of elements (Players) in this table)

Then I convert that (number of players) into a string, so that it can fill the text field of the TextLabel

Then I set the text of the TextLabel to this value

After doing this, I am going to use two events - PlayerAdded and PlayerRemoving - to detect when the number of Players changes. This is better than using a loop because these events are built in to the engine and more efficient since they only fire when the action occurs rather than checking all the time. The code, with that added, looks like below:

local Players = game:GetService("Players")

local TextLabel = Instance.new("TextLabel")

local NumberOfPlayers = #Players:GetPlayers()

NumberOfPlayers = tostring(NumberOfPlayers)

TextLabel.Text = NumberOfPlayers

Players.PlayerAdded:Connect(function(Player)
    NumberOfPlayers = tonumber(NumberOfPlayers)

    NumberOfPlayers = NumberOfPlayers + 1

    NumberOfPlayers = tostring(NumberOfPlayers)

    TextLabel.Text = NumberOfPlayers
end)

Players.PlayerRemoving:Connect(function(Player)
    NumberOfPlayers = tonumber(NumberOfPlayers)

    NumberOfPlayers = NumberOfPlayers - 1

    NumberOfPlayers = tostring(NumberOfPlayers)

    TextLabel.Text = NumberOfPlayers
end)

The above code is what you are looking for. I would recommend adjusting the TextLabel (referring to the variable in the code, not the instance) by assigning that variable to the actual TextLabel that you want the code to apply to.

Hope that helps!