Tap any Office app like Word to launch it.
Enter your email address and tap the arrow.
Enter the Password associated with your email address > tap Sign in.
Tap Start using Word to get started with the app.
If you have other Office apps installed on your Android device, your account and OneDrive files will be automatically added.
To add another account, tap Open (or Open other documents if you're on a tablet) > Add a place.
If you are using OneNote, tap Settings > Accounts.
Choose the cloud service you want to add, such as OneDrive for business or Dropbox.
Enter your email address and password that you use to sign into that service.