Unable to open 'NoteStore.sqlite "file because its format is not correct.

You might want to consider starting a new discussion. Since this one is marked solved, less people are likely to look at it. A new post would be much more visible. You can link to this one.

Link hasn't posted in the ASC for a year or more. Try your second sentence.

This procedure will revert the whole Notes database to a previous version. It's not possible to restore individual notes.

Please quit the Notes application if it's running.

1. Triple-click anywhere in the line below on this page to select it:

~/Library/Containers/com.apple.Notes

Right-click or control-click the highlighted line and select

Services ▹ Reveal in Finder (or just Reveal)

from the contextual menu.* A folder should open with an item named "com.apple.Notes" selected. Move the selected item to the Trash, then restore it from a backup that predates the unwanted change. If you back up with Time Machine, enter it and select the snapshot from which you want to restore.

2. Do as in Step 1 with this line:

~/Library/Group Containers/group.com.apple.notes

This time the selected item will be "group.com.apple.notes", or you may get an alert that the item doesn't exist. If the latter happens, skip this step.

3. Log out or restart the computer and empty the Trash. Launch Notes. You may see a "Welcome to Notes" splash screen, as if you had never launched it before. Click Continue.

4. If you synchronize Notes with iCloud or another network service, the notes you restored may be immediately deleted after you restore them. In that case, temporarily disconnect from the Internet, for example by turning off your broadband adapter, and restore again. Copy the contents of each note to a document in another application, such as TextEdit. Reconnect to the Internet. If the notes are deleted, recreate them from the TextEdit document. They should then synchronize to the network.

*If you don't see the contextual menu item, copy the selected text to the Clipboard by pressing the key combination command-C. In the Finder, select

Go ▹ Go to Folder...

from the menu bar and paste into the box that opens by pressing command-V. You may not see what you pasted because a line break is included. Press return.

If you are not using TimeMachine, how can I restore the com.Apple.notes file?
Can I also just delete it and restart notes and re-link to iCloud?

You can just delete it.

I didn't use Time Machine too and my notes application works after I deleted it.