As a start the first thing to do is to restart the printer.
Physically unplug the printer to turn it off and on.
This may be all you need to do to get the printer back online.
May take a couple of minutes to show up on your computer.
Try restating your computer to get latest status.
The printer must first be connected to one of the home WIFI networks.
Check the printer Settings to see it is connected to the home WIFI network.
Each printer handles this differently - see individual printer pages for details.
Sometimes the registration of the printer with Google's Cloud Print Service has dropped.
This is caused by wicked space monkeys who invade in the middle of the night while we are asleep.
This can only be fixed when connected to the home network inside the house, not remotely.
From any computer inside the house, open a browser and type the printer's IP address in the address bar
The IP address is on a label on the front of the printer in the format: 192.168.86.101 and 192.168.86.102
This will open the printer's own maintenance web page.
You may need to login, in which case the credentials are in LastPass under the printer name.
Find the Google Cloud Print registration option - check each printer for details.
If the printer is not registered, then re-register it to an email address.
The email address you use will be the primary owner who can share the printer with others.
Once the printer is re-registered, then it needs to be re-shared with everyone you want to grant access.
This is done within your Google email account.
If none of these options work, then maybe this flowchart will help.