Hi,
CalenGoo can sync directly with Google Calendar or via the Android calendar, depending on which account you activate or enter under "Settings > Accounts". The backup saves only data from CalenGoo's own database, not from the Android system's calendar database. To make this clear the backup screen shows which calendars are included in the backup.
By default CalenGoo syncs via the Android calendar, which usually works fine. And the Android calendar then syncs itself with Google Calendar:
CalenGoo <-> Android calendar <-> Google Calendar
If nothing is in CalenGoo, please check which accounts are checked under "Settings > Accounts" in CalenGoo and which calendars are visible under "Settings > Visibility/Download". Is everything correct there?
Is the Samsung calendar empty, too? That would probably mean that your Android calendar is empty, maybe something went wrong with its sync. It might fix itself after a while or you can try to fix it, maybe in the "Settings" app by turning the calendar sync off and on again or maybe by using "clear data" on the "calendar storage" app (but you should download a backup first from
http://calendar.google.com as a security precaution).
Until this is fixed, you can just sync CalenGoo directly with Google Calendar by adding your Google account under "Settings > Accounts > Add account > Google" in CalenGoo.
Please don't hesitate to contact me again if you have further questions!
Kind regards
Dominique Gunia