Starting in San Diego La Jolla should be your first stop. The Cove there is world famous, both it and the Shores 1/2 nearby are so popular that I doubt you'll have much trouble finding someone to show you around. IBDivers LaJolla should have everything you need for suit rental tanks/weights etc. Here's a resource for San Diego diving -
www.divebums.com - you probably can't do all the good San Diego shore dives in one day.
The Cove is so popular that you may not get a parking space much after 9am on weekdays, 7am on weekends - so plan accordingly. Not a huge problem since there' s street parking elsewhere - even the garage at the bank up the hill in LaJolla, the stairs to the side run right down to the top of the Cove but it cuts into your time a lot. We planned to do two Cove dives and be out by 10:30 - at noon we were just getting out of the water since I had to drop my friend/gear then find parking about a mile away. Also they're really proud of their red curbs and the ticket is expensive. Anytime you see any open space - look twice.
As you move up the coast a couple hours there's also a lot of diving around Laguna Beach. Several sites are very close by and very popular with divers. On the link "Max" provided above - those sites are Heisler Park, Shaws Cove and how can there not be divers at Divers Cove...
Beach Cities Scuba in that area for rentals - they have several locations.
It would be possible to morning dive in La Jolla then move up the coast to Laguna for afternoon dives - about a 2? hr. or less drive depending on traffic. Since it seems you're trying to move up the entire west coast in a week...
If you plan to stay a day somewhere around the Long Beach area, Catalina Island is an option. You can haul gear on the Catalina Express Ferry - they're used to seeing divers with gear - and even come back the same night as Catalina resorts are pricier. The Ferry leaves from Long Beach harbor, Dana Point farther south or San Pedro. You want the one going to Avalon. Diving there is in the Marine Park. I haven't been there in a decade so am not current on what the facilities are like now.
Vets Park in Redondo Beach is also a popular dive site a little farther north. IDK anyone in that area. Pacific Wilderness possibly - they're a little south in San Pedro. Ask them about options for getting out into the Kelp of the old Marineland site also - might be someone doing it the day you're in the area. If not it's really tricky to try on your own, the surge beats you up if it's not flat calm and the cobbles shift underfoot.
I'd skip
all the diving from Redondo thru L.A. and drive to at least Santa Barbara, Ventura or possibly even Monterey if you wanted to spend all day getting there. It's not the distance it's the traffic. I've always wanted to dive Morro Rock though also - it just looks like it could be a good dive.
IDK much past that except I believe you need reservations to dive at Pt. Lobos - which I understand is worth the trouble to get. Monterey Aquarium is worth a stop if you have time while in the area.