+1 on SP Taylor. If you don't live exactly in SF then you can take BART and ride from the Embarcadero station across the Golden Gate Bridge and through Marin.

Another overnighter would be to go to Del Valle Region Park near Livermore. Take BART east to Dublin-Pleasanton station and then bike 20 miles (big hill though) to the park.

A good springtime multi-day trip is to go to Yosemite...Perhaps take the BART east to the Dublin-Pleasanton station and go from there...About two nights/three days one way.

To learn bike touring, a good idea is to take a couple of single overnighters to shake down your equipments and methods. As was suggested, make lists of what you took and used, didn't use, and shoulda/coulda used.

You will quickly get the hang of it.