Who are you arriving on into LAX? If DL you'll most likely arrive at T2 where you'll clear customs and immigration. However some flights arrive at TBIT . Any DL partner except VS will also arrive at TBIT. Once through formalities, drop bags at the bag recheck belt. Then proceed to clear security. All terminals except for T1 are connected post security. T2/3/TBIT are connected via airside shuttle. Depending where you flight is going it will depart out of T2 or 3. There's one gate used in TBIT, thus unlikely to be from there.