Things to do in October

Hello!

I’m (23F) currently planning a trip from Chicago to SF with my best friend (28F) in October, we will be staying 4 full days. We are already planning to go to the Alcatraz, Muir Woods and see the Golden Gate Bridge. However we want more ideas and recommendations on where else to go. No tours please!! We want to rent a car to visit some of the other towns nearby like Monterey/Santa Cruz, Napa and Sacramento. Still deciding so please leave suggestions on which cities/places are worth visiting! We are huge foodies so what are some of the best restaurants and food spots that are worth the hype? We are very open minded and want to do the most in the 4 days we have. Also would love to go whale watching however from reading online the season for that tends to be December-May, would it be worth going in October? TIA!!