Save/Load Data not working correctly?

I am finishing up a game I have been working on for a few weeks, I had the load/save data working properly but now when I test my game the data will not save I believe. Whenever I leave the game the console says "attempt to index nil with Cash" even though the Cash value (the nil) does exist. Am I not calling the value correctly? Thanks in advance!

local DataStoreService = game:GetService("DataStoreService")
local CashStore = DataStoreService:GetDataStore("Cash") 
local KillsStore = DataStoreService:GetDataStore("Kills")
local player = game.Players.LocalPlayer
local NPC = game.Workspace.NPC:WaitForChild("Humanoid")

local STARTING_CASH = 100

local function onPlayerAdded(player)
    local playerKey = "Player_" .. player.UserId
    wait()
    print("User ".. player.UserId.. " Joined")

    local leaderstats = Instance.new("Folder")
    leaderstats.Name = "leaderstats"
    leaderstats.Parent = player

    local Cash = Instance.new("IntValue")
    Cash.Name = "Cash"
    Cash.Parent = leaderstats

    local Kills = Instance.new("IntValue")
    Kills.Name = "Kills"
    Kills.Parent = leaderstats

    local myCash
    local success, err = pcall(function()
          myCash = CashStore:GetAsync(playerKey) or STARTING_CASH
    end)
    if success then
        Cash.Value = myCash
        print("loading "..Cash.Value)
    else
        print("failed to retrieve Cash")
        warn(err)
    end

    local myKills
    local success, err = pcall(function()
        myKills = KillsStore:GetAsync(playerKey) or 0
    end)
    if success then
        Kills.Value = myKills
        print("loading "..myKills)
    else
        print("failed to retrieve Kills")
        warn(err)
    end

This is the part of the script that loads the data. I don't think anything is wrong with this part but I could be wrong.

local function onPlayerLeft(player)
    wait()
    local playerKey = "Player_" .. player.UserId
    local myCash = player.leaderstats.Cash.Value
    print(myCash)

    local success, err = pcall(function()
        myCash = CashStore:SetAsync(playerKey)
    end)

        if success then
            print("User "..playerKey.." saved with "..myCash.." in the bank")
        else
            print("error")
            warn(err)
    end

    local myKills = player.leaderstats.Kills.Value
    print(myKills)

    local success, err = pcall(function()
        myKills = KillsStore:SetAsync(playerKey)
    end)

    if success then
        print("User "..playerKey.." saved with "..myKills.." in the bank")
    else
        print("error")
        warn(err)
    end
end
game.Players.PlayerRemoving:Connect(onPlayerLeft)

This is the part that saves stats, or it is supposed to. Again, the console prints "attempt to index nil with Cash". This will be my first game so I still haven't figured this all out quite yet. Save and load data are confusing to me.