Open the Notes app
Tap Folders
Tap Recently Deleted
Find the note you want
Open the note
Tap Recover
Check the Notes app main folders if the note was moved instead of deleted
Check iCloud Notes if you use iCloud sync
Check other email accounts linked to Notes
Use Search in the Notes app to look for the note title or keywords
Check the Notes app on iPad, Mac, or another device signed in with the same Apple ID
Restore from an iCloud backup if the note is not in Recently Deleted
Restore from a computer backup if you made one with Finder or iTunes