Hi there Oliverabbybridgett,
If you're missing a notes folder on your iPhone, and you followed all the steps in the related article If you're missing notes on your iPhone, iPad, or iPod touch, the notes may be gone for good. Did you follow these specific steps from that link to check your account settings?
"Check your account settings
If you store your notes with a third-party account or email service, like Gmail or Yahoo, check your settings:
- In the Settings app, tap Mail.
- Tap Accounts, then tap the email account that you want to check.
- Make sure that Notes is on.
If you use Notes with more than one email account, just repeat the steps for each account. If your account is missing, learn how to add an email account to your device."
Also, do you use iCloud for your Notes? If you don't, it's possible the note might be included in a recent backup, and you can check for a backup with these steps: Locate backups of your iPhone, iPad, and iPod touch
Thanks.