San Diego and surfing belong together, and you do not need years of experience to get a taste of it. The coastline offers numerous surf areas, but beginners should approach the Pacific with respect rather than simply renting a board and paddling out anywhere.
Take a lesson
If you have never surfed, a lesson is worth considering. An instructor can help with equipment, positioning, basic technique and understanding local conditions.
Choose the right place
A beach that is suitable one day may behave very differently another day. Swell, tides, currents, weather and crowds all matter.
Ask local surf schools or lifeguards about current beginner conditions rather than relying solely on a generic online list.
Learn basic etiquette
Surf lineups have rules and expectations. Do not paddle straight into crowded experienced breaks without understanding right of way and safe spacing.
You can enjoy surfing without standing up
Your first session may involve more falling than riding. That is normal.
I would judge success by whether you enjoyed being in the water, learned something and want to try again.
And if surfing turns out not to be for you, sitting on a San Diego beach watching people who are good at it remains an excellent backup plan.