One of the best spots in San Diego and is a MUST to visit, is the PACIFIC BEACH CRYSTAL PIER, Located just 15 minutes away from Downtown San Diego, the best Time to visit is on Summer or Spring (with less attendance), However the Pacific Cold waters, the restaurants, the people around with a San Diego Laid-Back Style will impressed you.
Dont Forget TO BRING WATER, and Some Snacks, However all around the place you´ll find amazing spots and Restaurants to eat, I Do recommend to you Fillipi´s PIZZA located just few blocks from the Pier on the Same Street.
San was on my travel list in 2020,but unfortunately Covid came for a visit and destroyed our plans 
Maybe I’ll get there one day 