Getty Museum does not have reservations, EXCEPT for a PARKING SPACE! Not possible to get except far in advance. Just show up and the tram will take you up the hill.
Buildings and garden more interesting then the art as far as I could see.

How about a day at the beach. Venice, Santa Monica, or Manhattan Beach. A short trip from the airport. You might even find a hotel shuttle to get you there.

Shop till you drop in Beverly Hills.