Fish Market is down at the south end past the USS Midway. Its pretty good. We have had really great meals there. The last one in march before a 5 night on the Wonder was okay. Nothing really wrong just not as spectacular as times past. We usually stay at the Wyndham Bayside and its a easy walk.
Also "little Italy" is just up about 3-4 blocks up from the waterfront park. To be honest we have eaten here 3-4 times always a different spot and they have always been really good. We usually just walk up there and check trip advisor and find something that is rated well.
Depending on where staying both of these options are short uber/lyft or a walk away
We are from Phx, AZ and got to San Diego a couple times a year to escape the heat. We like to stay at the Wyndham bayside. Its not super expensive and is right on the water. No brainer for the port as its across the street and they have stay/parking packages for the cruises.