How do I transfer inventory items between places within a game?

I have a script that saves stats between places, but I'm newer to scripting and don't know how I'd go about doing the same with items in your inventory, including items that aren't in the starter pack. Here's the script I'm working with (not mine)

    --[[Savin'
            Dem
                Stats  
    --]]
    game.Players.PlayerRemoving:connect(function(player)
        local datastore = game:GetService("DataStoreService"):GetDataStore(player.Name.."Stats")

    local statstorage = player:FindFirstChild("leaderstats"):GetChildren()
    for i =  1, #statstorage do
        datastore:SetAsync(statstorage[i].Name, statstorage[i].Value)
        print("saved data number "..i)

    end
    print("Stats successfully saved")  
    end)


    --[[
        Loadin'
            Dem
                Stats
    --]]
    game.Players.PlayerAdded:connect(function(player)
            local datastore = game:GetService("DataStoreService"):GetDataStore(player.Name.."Stats")

        player:WaitForChild("leaderstats")
        wait(1)
        local stats = player:FindFirstChild("leaderstats"):GetChildren()
        for i = 1, #stats do           
        stats[i].Value = datastore:GetAsync(stats[i].Name)
        print("stat numba "..i.." has been found")
            end
end)