Walk along Abbot Kinney Blvd from Westminster to Venice and back. It's a fun street to walk and window shop - lots of popular "online" brands you don't commonly see brick & mortar storefronts for, like Mejuri and Cuyana. Stop in Huset for the Scandinavian gummies and grab a slice of pizza from Gjelina's to-go section. If you get tired, go to the back of Goodr (sunglasses shop) and sit in the back patio. There's an Erewhon at the south end of Abbot Kinney/Venice if you want to stop in and look around.
In 1905, Abbot Kinney built "Venice in America" in reference to Venezia in Italy. It was a few square miles of canals, much of which was paved over in the 1930s. A mile and a half length of the canals still exist and is open to the public. Peaceful spot away from cars.
Fantastic sandwich spot on house made focaccia. Pick up your sandwich and walk to the middle school on Lincoln/Montana to picnic on the lawn. Stop in Zibby's bookshop on your way there or back.
Saturday morning farmers market from 8 AM - 1 PM on Arizona from 2nd-4th street.
If you're a pastry person and willing to wait at least 30 minutes in line for a damn good croissant, this is the place for you.
Open from 8 AM - 4PM everyday on the UCLA campus. Free to all visitors and a great place to picnic, rest, or walk.