OK.... how 'bout if I throw this out there. Assuming you're talking about South Cardiff State Beach, this is not a dive I would recommend for new divers. You have two points of entry for this shallow reef diver, neither is easy. You can park at the South end of the parking lot of the State beach, but the swim to the reefs is long, very shallow, and you have to go way out, then south, past the surfers.
Alternately, you can walk South along the beach, but it's rocks, loose sand and a long way down to the beach below Tide park, which is your next entry point. I usually park at Tide Park on the street above, but there's a stair you have to traverse with 145 steps to it, quite a haul up when you're tired and soaking wet.
The reefs are very shallow on top, and can be quite deceiving, you'll want to stay way North or way South of the reefs until you get past the shallowest part. It's one of the longest shore dives I do in So-Cal. The actual reefs once you kick out are in 20'-30', depending on the tide. You can always dive straight out from the parking lot, but as far as I know, that's just sand.
There are much better dive sites in San Diego for someone just starting out. Wherever you go, dive safe, have fun and come back from the dive.
