You are retired, take your time. Get off the train in Emeryville. Assemble bike and pack your panniers. Then take a shuttle bus to Fisherman's Wharf bus stop. Then ride your bike west, then north across the Golden Gate Bridge, and check out some of the sights north before you go see family. There was a Safeway grocery store just west of Fisherman's Wharf you could pick up a few days of groceries, it was there when I was there in 2014. I stayed at the Fishermans Wharf Hostel, but I have no clue how hostels are doing with a pandemic. There also was a hostel in Sausalito eight years ago, that is another option.

Some but not all California state parks have hiker biker sites, no reservation needed, those sites charge per person for those on bikes. The last state park I stayed at in 2014 before I rode to San Francisco was Samuel P Taylor State Park. Distance to Samuel P Taylor is far enough you might want to stay a night in San Francisco or Sausalito after your train ride.

The night before Taylor park, I stayed at Sonoma Coast State Park, I was going south, not north. You would have to check their websites to see if they still have hiker biker sites.

Then head east to see family from there. There you would be on roads I have not been on, but you would not be going far.

Along the coast you would be traveling North against prevailing winds, but you don't need to go too far before you turn east to see family.

You will never forget riding your bike across the Golden Gate Bridge to start your big bike tour.





If my recollection is right this photo is the hiker biker site (in 2014) at Samuel P Taylor.



All the locations I cited here are from my 2014 trip, you would need to make sure that things like shuttle buses still exist.