Hello Herb,
Welcome to Microsoft Community.
Can you clarify here whether you have been using a Microsoft account password or a local account password? If you are using a Microsoft account password, have you changed your Microsoft account password recently?
The key to this error message is that your computer is offline at this time. If you have recently changed your Microsoft account password, or if the device has not been used for a long time, or if the device has been offline for a long time, when you connect to the network again and are asked to enter your password, this prompt will appear and ask you to use the password you last logged on to the device. As a friendly reminder, this password is most likely the last password you used for your local account.
So now you need to confirm what other options you can see on the login page and what else you can do at this point. If you don't see "reset password" or any of the other login options available, and only see a prompt asking you to log in with your last password, then that's the only thing you can do on the login page right now. In this state, even if you enter safe mode, you will probably see the same prompt.
If you really can't recall the last password, you'll need to create a Surface-specific recovery drive on another Windows computer and use it to restore your Surface:
Creating and using a USB recovery drive for Surface - Microsoft Support ****
The full procedure is in the video at this link and it is recommended that you watch the entire video in its entirety before performing this action.
Best Regards,
Mitchell | Microsoft Community Support Specialist