[Solved] How do i save multiple value with DataStore ?

Doesn't say a number value says a nil value. Your code doesn't make a lot of sense you said if Data then, (which checks if it's nil), then tried to use it in an else statement. You can't save Data when there's no Data? Also why are you trying to save Data when the player joins, SetAsync should be in a separate function.

Edit: So your code should look like:

local DataStore = game:GetService('DataStoreService')

local UserData = DataStore:GetDataStore('Data')

local Key = 'Player-'

function WhenPlayerJoin(Player)
    local Leader = Instance.new('Folder')
        Leader.Name = 'leaderstats'
        Leader.Parent = Player

    local Money = Instance.new('IntValue')
        Money.Name = 'Money'
        Money.Parent = Leader

    local Kill = Instance.new('IntValue')
        Kill.Name = "Kill"
        Kill.Parent = Leader

    local Data = UserData:GetAsync(Key..Player.UserId) 

    if Data then
        Money.Value = Data[1] 
        Kill.Value = Data[2]
    else
        Money.Value = 0
        Kill.Value = 0
    end

for i, child in pairs(Leader:GetChildren()) do
    child.Changed:connect(function()
    UserData:SetAsync(Key..Player.UserId,{Money.Value,Kill.Value})
    print("Data Saved")
    end)
end
end

function PlayerLeaving(Player)
    local Money = Player.leaderstats.Money
    local Kill = Player.leaderstats.Kill
    print("The stats are there")
    UserData:SetAsync(Key..Player.UserId,{Money.Value,Kill.Value})
    print("Data Saved")
end
game.Players.PlayerAdded:connect(WhenPlayerJoin)
game.Players.PlayerRemoving:connect(PlayerLeaving)

Edit I really reccomend using pcall in case of any DataLoadingErrors: http://wiki.roblox.com/index.php?title=Global_namespace/Basic_functions#pcall