The Getty is one of the most iconic art museums in LA: great exhibits, amazing views, and beautiful gardens. Admission is free (just reserve a time online). There is also the Getty Villa (Pacific Palisades) which focuses on ancient Greek and Roman art. These grounds are also stunning and recreate an ancient Roman home.
A fun way to spend a sunny day nearby: watch beach-goers and the surf, ride on the ferris wheel, and play some arcade games. This is super walkable from most hotels.
There are a lot of different ways to explore Venice, each offering their own character. - Venice Boardwalk: this is a busy beach-front path lined with shops and restaurants and filled with both locals and tourists. It has got a little bit of that original gritty Venice vibe to it still. - Venice Canals Historic District: a tucked-away neighborhood with beautiful homes and canals instead of streets, this scenic neighborhood is a great place for a stroll. - Abbot Kinney Blvd: this street has a plenty of elevated shops and delicious cafes and restaurants for you to leisurely spend a small chunk of the day.