i need help to access my locked notes in my iphone. Tried to reset the password but it’ll only work on new notes.

You’ll have to figure out the password you used.

“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.”

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