When I did Pacific Coast in 2014, we took Amtrak to Portland OR, then a bus to Astoria, I think we bought the bus ticket as part of our Amtrak ticket.
In Astoria we found a pizza place that had a cardboard recycling bin out back to dispose of our bike boxes. Box disposal could be an issue if you do the same. By the time we were rolling in Astoria, it was after dark. We anticipated that and had a nearby motel reservation for one night.
Then rode to San Fransisco. We also did a few days of sightseeing there. Stayed at the HI Hostel on Fishermans Wharf, but I have no clue if hostels are operating these days.
Got a Amtrak shuttle bus from Fishermans Wharf to Emeryville Amtrak station for our return home. Fishermans Wharf was surprisingly deserted, but riding to the bus stop at 5am, there are no tourists to be found.
