How do i make a global(across ALL servers) queue?

you could use http service, the easiest way..

or you could get creative with datastore service.

in order to use HTTP service, you need an external server/website.. and you could make servers constantly request and update the information on your web server;

in this example whoever, I'll try to get creative with data-store service,

lets say for example that i am making a thing that displays the name of the player with the most money in the game....

local data_name = "playerWith_MostMoneyInThisWonderFullgame"
local global_key = "theRichestPlayerKnown"
local money_key = "MostMoneyyyyy"
local datastore = game:GetService("DataStoreService"):GetDataStore(data_name)
local players = game.Players

local surfaceUi = workspace.board.surfaceGui.textlabel

local function newRichestPlayer(player)
    if player then
        local money = player.leaderstats.Money
        pcall(function()
            datastore:SetAsync(global_key,player.Name)
            datastore:SetAsync(money_key,money)
        end)

        surfaceUi.Text = player.Name.."\n"..money

    end
end



players.PlayerAdded:Connect(function(player)
    local playerWithMostMoney;
    local money

    pcall(function()
        playerWithMostMoney = datastore:GetAsync(global_key)
        money =datastore:GetAsync(money_key)
    end)

    if playerWithMostMoney then
        if player.leaderstats.Money.Value > money then
            newRichestPlayer(player)
        else
            surfaceUi.Text = playerWithMostMoney.."\n"..money 
        end
    else
        print("there is currently no known richest player")
        surfaceUi.Text = "unknown"
    end

end)


local co = coroutine.wrap(function()
    while wait(2) do
        local playerWithMostMoney;
        local money

        pcall(function()
            playerWithMostMoney = datastore:GetAsync(global_key)
            money =datastore:GetAsync(money_key)
        end)

        for _, player in pairs(players:GetChildren()) do

            if playerWithMostMoney then
                if player.leaderstats.Money.Value > money then
                    newRichestPlayer(player)
                end
            else
                print("there is currently no known richest player")
                surfaceUi.Text = "unknown"
            end

        end
    end
end)

co()

sorry this is not in the best form, i am kinda of in a hurry