San Diegans love their street festivals- at least once a month there is something going on.
Celebrate food and wine at the San Diego Bay Food & Wine festival - http://www.sandiegowineclassic.com/
The Artwalk in Little Italy is San Diego's largest urban festival celebrating the arts- https://www.artwalksandiego.org/
There are several music festivals- http://www.sandiegoindiefest.com/directions.html
Festivals celebrating neighborhoods and culture- http://www.littleitalysd.com/events/little-italy-festa/
That list just barely skims the top! When you come to San Diego, just check the listings to see what street festivals are going on while you're here.