There are plenty of opportunities, starting here in San Francisco with the SFAA (San Francisco Amateur Astronomers). We have two upcoming events, Saturday August 22nd on Mt. Tamalpais and Tuesday August 25th in the Presidio. More information on the SFAA Website.
There are weekly star gazing opportunities every clear Friday and Saturday evening at Chabot Observatory in Oakland.
|Chabot's "Nellie" Telescope|
The San Mateo County Astronomical Society hosts events in San Carlos twice a month at Crestview Park. Check the site for details.
Outside of the Bay Area you can find local and regional events with the NASA Night Sky Network locator for astronomical events across the USA.