Hi,
the automatic backup of CalenGoo's database includes all settings, events, calendars, and tasks except for calendars that are directly loaded from the "Android" account. And it does not include locally saved attachments.
If you want to make sure you have everything covered for a full restore without reconfiguring anything, it is recommended to use the backup feature in CalenGoo. You can access the backup settings under "Settings > Backups > Automatic backups" where you can create backups automatically every day, specify how many backups to keep, and manually create a backup as needed. There you can also see which calendars will be included in the backup.
Restoring from a backup is also straightforward through the same settings menu.
Please don't hesitate to contact me again if you have further questions!
Kind regards
Dominique