Guangzhou (CAN) to Wuhan (WUH) then to San Francisco (SFO)

First of all, I'd say your time is too tight for transfer unless you are flying with the same airline. Anyway, here are the procedures: Flight Arrival- Luggage Claim- Go to International Terminal by free shuttle bus- Quarantine & Inspection- Customs Inspection- Check in- Immigration Inspection- Security Check- Waiting for Boarding.

the flights are with the same airline. If I miss the connecting flight, do you know, will they accommodate me on another flight?

If you miss the onward flight on your own, I'm afraid they may not arrange another one for you free of charge. Then you have to buy another ticket. Or refund and get a new one in advance. Anyway, since the airline arranges both flights, the time can generally be enough. If still worried, you can reconfirm with the airline in advance. Good luck！