If you don’t mind traveling a bit out of WS you should go to the post office on 4th, make an appointment first though. We got the run around from Bartels, something about a special seat needed to recline the infant, which they apparently didn’t have. Post office was way more organized and helpful.
The Rite Aid at Westwood Village takes passport photos. If you called ahead you might be able to determine what accommodations need to be made for the newbie?