Yes, I was 52 when I moved from San Diego to Phoenix four years ago. I had less than a week to prepare before the packers and movers arrived. My things were in storage for three months while I lived in corporate housing pending finding a permanent place to live. Once I found a permanent home my corporate housing ended and all of my stuff was delivered to my new living room. There was a sense of urgency to moving, as I could not move around my new place with all the boxes and stuff were put and/or given Here's what I took away from that experience:
I kept most, but not all of them. If I had a connection to the book, I kept it. If not, I donated it.
Rent or sell what?
Unless you have family heirlooms or irreplaceable vintage furniture, donate/gift all of it and buy new. Your existing furniture won't fit in the new place and you will replace it anyway, so why pay to move it?
Absolutely yes! They get stale and lose potency. Also, get rid of any food that is hanging around your cabinets and pantry. I'm certain there's a food drive in your area that would be happy to accept unopened, unexpired food. Anything that has been opened needs to go.
I would also do a purge of your clothes. You are moving to a different climate zone, so you won't need as many cool-weather and rain-oriented clothing in LA as you do in SF.
Lastly, the day one of my closet shelves collapsed under the weight of "stuff" I did a second purge. Never again do I want to hear a crash and realize my home is literally collapsing under the wight of "things."