There are 4 ways.
Way 1: Locate and select the Save command on the QuickAccess toolbar. Click the Save Command.
Way 2: If you’re saving the file for the first time, the Save As pane will appear in the backstage view.
Way 3: You’ll then need to choose where to save and what to name the file. To save this document on your computer, select Computer, then click Browse.
Way 4: The Save As dialog box will appear.