Parking right at the restroom area. I believe "paid" beach parking in those lots.

I am not sure caue I haven't parked at the beach in years but the street right before you get to this area is Brookhurst. There was free parking along the roadside there (years ago, not sure anymore). There is also a part of the trail that takes you straight over to SART without hitting the restroom area.

click on TH's link, then pan up and slightly left, you can see the trail. There may also be small shopping centers on Brookhurst where you can park.