Thanks for sharing your feedback! For answers to your OneNote questions, see our Help and Support articles in the Account section of the app. You can also go to https://support.microsoft.com/onenote and select OneNote for Android at the bottom of the page.
We're sorry you're having trouble with OneNote. Sign in to onenote.com to make sure your account credentials are correct and retry again in the app . If you continue having trouble signing in to the app please send an email to onandroidfb@microsoft.com or send us feedback in the OneNote app by tapping "Send Feedback to Microsoft".