|Surf fishing on a calm day (swells < 4') is perfectly acceptable family activity, and it's super simple. It's necessary to maybe get knee deep in the water at most. When the kids get bored with fishing, they can play in the sand.
Simple carolina rig with #4 hook, up to 1.5 ounce weight, and some type of artificial grub is what you need. You can find surf perch on most of the beaches from south of monterey down to santa cruz.
Also if you go the DFG website and look for "MPA's", you will find a list of the protected areas.
The piers are terribly over fished, so about the only time you can catch something is when the bait fish (sardines, mackerel) are around (summer).