1. Download the app for your device:

    iPad or iPhone: App Store

    Android tablet or phone: Play Store

    Windows tablet or phone: Microsoft Store

  2. The first time you use the Word app, sign in with your Office 365 name and password.

  3. On the New screen, create a new document by selecting OneDrive - Personal under Create in, and then choose Blank Document.(Changes are saved automatically.)

    New OneDrive

  4. To give your document different name:, choose File > Save > Rename this file.

Source: Microsoft