If you belong to the latter group, you might find the following information useful. I am going to link to a number of kayaking groups/clubs that you can join and go kayaking with other people.
1. Kayakers' Alliance meetup group
My favorite, this group has a nice mixture of kayakers who own their own kayak and those who don't. Paddles are held in locations all over the greater San Francisco Bay Area. Many outings are done at locations where one can rent a kayak. Some events are held where there are no rentals. It started only a few months ago but has grown to become one of the most active.
2. Lodi Paddle Club meetup group
3. North Bay Kayakers meetup group
4. Northern California Kayaks - Suisun City meetup group
5. Sacramento Paddle Pushers meetup group
6. Western Sea Kayakers (WSK)
This is a "real" club in the sense that they charge a due and have meetings.
7. San Francisco Bay Area Sea Kayakers (BASK)
This is another "real" club in the Bay Area.
If you know or other kayaking organizations in the San Francisco Bay Area, please let me know and I will add to this list.