WHAT’S HAPPENING TODAY, Friday, Aug. 6 La Jolla • The La Jolla Music Society presents SummerFest Opening Night: String Spectacular, 7:30 p.m., La Jolla Museum of Contemporary Art, Sherwood Auditorium, 700 Prospect St., (858) 459-3728, $40-$60 WHAT’S HAPPENING TOMORROW, Saturday, Aug. 7 Pacific/Mission Beach • Blood drive, 8:30 a.m. to 2:30 p.m., The Wave House, 3115 Ocean Front Walk, Mission Beach, put on by the Old Mission Beach Athletic Club, benefiting the San Diego Blood Bank • Clean PB Day, 9 a.m. to noon, Ocean Boulevard at Grand Avenue, www.cleanpb.com Board Silly, noon to 2 p.m., Pacific Beach/Taylor Library, 4275 Cass St., board games for adults, (858) 581-9934, free La Jolla • Children’s Stranger Awareness & Avoidance & Bully Self-Defense course, 11 a.m. to 1 p.m., La Jolla YMCA, 8355 Cliffridge Ave., (858) 453-3483, $30 members/$40 nonmembers