Hi LMY11,
Thank you for posting in the Apple Support Communities. It sounds like you may have made a backup with your computer, correct? If so, we can help! Check out the links below to see what is included in both types of backups, and how to restore your device from a backup.
About backups for iPhone, iPad, and iPod touch
Restore your iPhone, iPad, or iPod touch from a backup
If you restored your device without backing up to a computer, and did not store your missing content in iCloud, the would be no way to retrieve the missing content.
As for the missing notes from Notability, you may want to review this article for info on how to recover the data:
Recovering Deleted Notes – Notability
We hope that helps!