Henry Coe (Morgan Hill) is a great spot to camp. It's a HUGE park and has several lakes to fish. However, the hike up to the lakes is a bit brutal and takes several hours.
They also have a camp sight at Lake Del Valle (Livermore). The fishing is great, and there's no hike. There also have boat rentals. However, it is a camp sight, so it's not very secluded and there will most likely be several other people nearby camping.