Derping Out? (SIMPLE SCRIPT)

For one thing, please place your code in a code block in the future.

Another, the reason the script is not working is because the variable is the value of the Players Service's NumPlayers at the time it is taken. Meaning whatever number the script got from game.Players.NumPlayers is the number it will remember. You would be better off placing the game.Players.NumPlayers in the if then statement.

while true do
    if game.Players.NumPlayers == 2 then --The script will take NumPlayers from the Players Service directly.
        print('It Worked')
    end
    wait(1)
end

Your code could however cause lag if you continue to have while loops in multiple scripts. I would recommend using the .Changed event for a cleaner code (I tested this script in studio but it would not print if the NumPlayers have changed).

game.Players.Changed:connect(function() --The event fired so the function will handle everything.
    if game.Players.NumPlayer == 2 then --This will only work if there are two players in game.
        print('It Worked')
    end
end)

You could use

while wait(1) do --Automatically waits 1
if game.Players.NumPlayers == 2 then
print("It Worked!")
end
end

But if you are wanting to see if the number of players are greater than or equal to 2 players (so that it doesn't only do stuff if there are specifically 2 players) do if game.Players.NumPlayers >= 2 then

Hope this helped

Adding on to the other answers, you could do this:

local ready = false

function command()
    print("It worked!")
    wait(5)
    ready = false
end

while wait() do --wait() is faster than wait(1)
    if not ready and game:GetService("Players").NumPlayers >= 2 then
        ready = true --debounce
        command()
    end
end

This way It won't spam if there is 2 players, it will run if there is 2 or more players, and it will run "command" where you could teleport players.

Hope it helps!