I'm confused on how to add something to a players starter pack using script?

This is my code.....

game.Players.PlayerAdded:connect(function(player)
    local folder = Instance.new("Folder",player)
    folder.Name = "leaderstats"
    local currency1 = Instance.new("IntValue",folder)
    currency1.Name = "Kills"

    player.CharacterAdded:connect(function(character)
        character:WaitForChild("Humanoid").Died:connect(function()
            local tag = character.Humanoid:FindFirstChild("creator")
            if tag ~= nil then
	         if tag ~= nil then
                    local killer = tag.Value
                    if killer ~= nil then
                        -- Find the killer's leaderstats folder
                        local killerStats = killer:FindFirstChild("leaderstats")

                        if killerStats ~= nil then
                            -- Find the killer's Kills IntValue
                            local killerKills = killerStats:FindFirstChild("Kills")
                            -- Increase Kills as before
                            killerKills.Value = killerKills.Value + 1

                            if killerKills.Value == 1 then
	                         -- *Right here I'd like to add an item to the starter pack* 
	                     end
                        end
                    end
               end
         	if tag.Value ~= nil then
        	end
           end
  	end)
    end)
end)

Does anyone know how to do this? If you do, PLEASE TELL ME!

Edit: format your code correctly! ~ incapaxx