Hello Crustal E,
Welcome to Microsoft Community and hope you are doing great today!
I'm Chris Jordan and I'd be glad to assist you with the questions.
Concerning your query, if you are on Windows 10 and 11, the Backup folder for your notebooks is located at C:\Users\user name\AppData\Local\Microsoft\OneNote\version\Backup. You may also use the steps below to enable see the sync OneNote data info from your google drive for your ref.
Step 1: Save your OneNote files on your PC. Then log in to your Google Drive on the web and hit New on the top left side.
Step 2: Select File upload or Folder upload according to your requirements. Alternatively, you can drag and drop OneNote files or folders to Google Drive.
Your kind understanding is highly appreciated. Stay safe and healthy always. If you have any questions or concerns, please do not hesitate to send them back.
Best regards,
Chris Jordan