Hey there...there are a few ways to get involved in a local dive scene, that will be true no matter where you're at. First, go visit all your local dive shops, and ASK if they have a dive club. If they do, join it! Go to all the club meetings and club dives. The goal here is just to get out there, and get to know the folks who are diving locally. Once you have a stable group of dive buddies, you can be pickier about what you attend, but for now - attend everything.
Are there events the local shops are hosting? Go to those! Even if they aren't necessarily the *most* interesting to you, or relevant...remember right now you are just trying to get out there, and get to know the local dive scene.
You also have a couple nice charter boats in San Diego (Waterhorse, etc); book dives and go out with them. When you do, introduce yourself to the other divers, and make a point of getting contact info (facebook, insta, phone numbers) for other divers who are local - let them know you're new and looking to make new dive buddies. Most folks are pretty forgiving of new divers; don't hide it.
When you meet someone on a shore dive, a meet-up, or a boat, who's local and who you "click with", get there contact info and then FOLLOW UP. Message them and ask them to go diving with you! Ideally, folks would ask you, but in practice you really have to be the one taking the initiative here.
Eventually, you'll find a few stable buddies you can rely on, who like to go diving about as much as you do, and who have similar dive styles and interests. When you do, and you're an experienced diver yourself with your own circle of buddies, pay it forward and be nice to the eager new diver looking to take their first steps into local diving...and have fun!
