Most of the beaches in and around Orange County (and the greater LA metro area) in general charge for parking but for a quieter, more secluded, and free beach, try Corona del Mar, just south of Newport Beach and just north of the Newport Coast Villas (Newport Coast). Parking in the communities (Irvine Terrace, Cameo Shores, etc) isn't allowed, but there is plenty of free street parking available on the side streets with just a short (two blocks maybe) walk to the State Park (versus the parking fee at the state park). Being less touristy than Laguna, Newport, or Huntington Beaches, finding parking on these side streets is a lot easier.