Why isn't my DataStore and Inventory Saving script working correctly?

Alright, so I have a Leaderboard script and it works fine but the problem is, that it's not saving my data or other players data and another problem I'm having is the tools, they're not saving when the player leaves the game after they bought it from my shop gui, I don't know why it's not working properly. please help.

The error I keep getting in my Leaderboard script is this:

ServerScriptService.Leaderboard:17: attempt to index global 'data' (a number value)

My Leaderboard script:

local dataStoreService = game:GetService("DataStoreService")
local dataStore = dataStoreService:GetDataStore("Currency")

game.Players.PlayerAdded:Connect(function(player)
    local leaderboard = Instance.new("Folder",player)
    leaderboard.Name = "Leaderboard"

    local cash = Instance.new("IntValue",leaderboard)
    cash.Name = "Cash"
    cash.Value = 50

    local recieved,failed = pcall(function()
        data = dataStore:GetAsync(player.UserId)
    end)

    if recieved then
        cash.Value = data[1]
        print("Data was received")
    else
        print("Data was not received")  
    end

    while true do wait(30)
        dataStore:SetAsync(player.UserId, cash.Value)
    end
end)

game.Players.PlayerRemoving:Connect(function(player)
    local leaderboard = player.Leaderboard
    local cash = leaderboard.Cash

    local saved,failed = pcall(function()
        dataStore:SetAsync(player.UserId, cash.Value)
    end)

    if saved then
        print("Data was saved")
    else
        print("Data was not saved")
    end
end)

My Inventory Saving script:

local dataStoreService = game:GetService("DataStoreService")
local dataStore = dataStoreService:GetDataStore("Currency")

game.Players.PlayerAdded:Connect(function(player)
    local leaderboard = Instance.new("Folder",player)
    leaderboard.Name = "Leaderboard"

    local cash = Instance.new("IntValue",leaderboard)
    cash.Name = "Cash"
    cash.Value = 50

    local recieved,failed = pcall(function()
        data = dataStore:GetAsync(player.UserId)
    end)

    if recieved then
        cash.Value = data[1]
        print("Data was received")
    else
        print("Data was not received")  
    end

    while true do wait(30)
        dataStore:SetAsync(player.UserId, cash.Value)
    end
end)

game.Players.PlayerRemoving:Connect(function(player)
    local leaderboard = player.Leaderboard
    local cash = leaderboard.Cash

    local saved,failed = pcall(function()
        dataStore:SetAsync(player.UserId, cash.Value)
    end)

    if saved then
        print("Data was saved")
    else
        print("Data was not saved")
    end
end)

Any help would be appreciated.