Locked notes

If you forgot your notes password:-

To unlock a note, you need to enter the password that it's locked with. If you forgot the password, Apple can't help you regain access to your locked notes. You can create a new password, but this won’t give you access to your old notes. A new password will let you password protect any notes that you create going forward with the new password.

from

https://support.apple.com/en-us/HT205794

Not unless you doecifically backed the phone up before putting the password on.

Note I said backed up, because icloud is by default a contemporaneous communication mechanism not a backup..