It depends...
if you can find an L.A. county certified EMS instructor where you're currently located than you should be able to get the Expanded Scope of Practice class before you move here.
If you can't find one, then you probably won't be able to. I don't believe that there are any online classes that teach the L.A. county scope, you must have a live instructor that's been certified by the L.A. County DHS.
If you wait til you move here there are a number of approved EMS educators on the L.A. County DHS website from which you can get the needed certificate. It's either a 3 or 4 hour class, can't recall off the top of my head.
I can recommend one instructor in particular, Emergency Concepts, based in the San Fernando valley area of Los Angeles. It's run by Fred Miller, a retired L.A. City Fire Dept. Paramedic. Classes are held at Valley Presbyterian Hospital every month and he's also willing to do individual classes if needed. He charges very reasonable fees and he's a good guy. I used his company to do my mandatory 24 hours EMT refresher class recently.
Good luck with your move.
John E