CA-1

• One of its kind drive. Don't miss it.
• Driving from North (say, from San FranciscO) to South is best because the ocean is just beside you.

Crater Lake

• The area from Lake Shasta to Crater Lake is really one of its kind: Sundial Bridge: Turtle Bay Exploration Park, Mount Shasta, McArthur-Burney Falls (One of the best CA State Parks, IMHO, particularly if you can go to the bottom of the falls), Lava Beds National Monument , Lassen Volcanic National Park - Don't miss any.
• Remember to carry water and food when you drive. These areas are not as better served as some of the other places we often visit.
• These places can be covered with minimal walking as well - just in case this is a requirement for you.

San Francisco

• Explore Stairway Walks in San Francisco.
• Get in touch with some good hiking groups. They may be able to tell you where to find free parking.
• Twin Peaks is a hidden gem, offering excellent views.
• Get your cartoon done on a sidewalk near fisherman wharf.

Napa

• St. Supéry offers self-guided, free, educative tour of the wine-making process. Some may find it better than the paid tours offered by others wineries in the Napa valley.
• Explore wineries offering deli and picnic-spots. V. Sattui Winery is one such. Their deli is quite innovative and their picnic area matches the taste.