If you live anywhere near the hurricane please take it seriously.
Your local government should provide sand, check their social media. Remove things from your yard. Go buy essentials. If you lose power keep your fridge closed as much as possible. Don't try to drive through flooded areas. Stay safe :3
Sand? They are speculating a year worth of rain in a very short time. Flash flooding is going to be insane. I suggest you do what we do during hurricanes on the right coast.
Evacuate.
Nothing is worth your life or the life of your family and friends.
There's been no evac orders yet for my area. It should settle down a bit before reaching landfall in SoCal. Sand can still help reduce flooding in your home even if you evac.
I never wait for the federal government to tell me when its a good time to leave.
Also consider when was the last tropical storm to hit SoCal? I was in Hurricane Gloria that made it to New England. that area hadn't been hit by a real cyclonic storm in ages. It was a bloody mess, no power for near a week, can't travel as all the roads have trees across them, etc.
The the same will happen there is its even a moderate tropical storm. Then if FEMA tells you to evac there won't be a viable route out. So like Gloria you are stuck in place in a desert climate in late summer.
Go to Scottsdale, have a mini vacation. If its a big nothing burger then you got nice few days out of LA. If it ends up a shit show you dodged a bullet w/ a nice few day w/o dealing w/ any of it.