One of my favorite places in the US. It is beautiful and has lots of old towns, ghost towns, monks who make jam and muffins in the summer, and wilderness for exploring. Great for camping.
If you are looking for a location of people who are just a little bit cooky and know it then you’ve found the perfect place.
San Francisco is a great place to visit with (or without) children. There are plenty of museums, cultural attractions, sporting events, and outdoor places to visit.
I’d skip Alcatraz and hit up Muir Woods, Fisherman’s Warf, and go on a boat tour of the bay. Whale watching is also a lot of fun if it is the right season. There is a great aquarium in Monterey.
If you like cultural attractions you should try visiting around a specific holiday, like the Chinese New Year.
Weatherwise the best time to visit (in my opinion) is October. Remember this is northern California so it can get pretty cool also windy. Bring a windbreaker.