Walk along the shoreline.
Forget the boardwalk, it’s absolute trash, there are always too many people, you can get bug bites and it’s not very pleasant to go barefoot.
If you 4km (about 2,5mi) from Venice Beach to the Santa Monica Pier is beautiful and freeing. It’s also totally doable for people like me who do absolutely no form of physical fitness.
You don’t feel the urge to be on your phone or even listen to music. It sounds dumb, but it’s totally true!
Also the farther down away from Santa Monica you go, the crowds thin. Nothing is as annoying as an over populated beach.