With all the trouble Office is having running under OS X El Capitan, you might want to try LibreOffice, which is now available free of charge via the Mac App Store. Because it’s in the Mac App Store, it’s likely to be regularly updated.
Making it prettier
You might considering installing the Office 2013 theme to make it look a little prettier (read the instructions on the webpage, beneath the illustrations, to learn how to install it).
I also like to open the Preferences dialog box (tap Cmd+comma) and click the Appearance heading beneath the main LibreOffice heading. Here you can change the colour of various on-screen elements. Changing the Application Background colour to something white, or nearly white, makes LibreOffice look a LOT more modern. Turn off Shadows too a little further down the list to make things look even better.
Save in Office file formats
To switch the app to saving in default Office formats, click the main menu, and then select Preferences. Click the General entry under the Load/Save heading, and in the Document Type dropdown list select Text Document, and then select Microsoft Word 97-2003 in the Always Save As dropdown beneath. Repeat this step for Spreadsheet and Presentation within the Document Type dropdown list, selecting Microsoft Excel 97-2003 and PowerPoint 97-2003 respectively too. Remove the check from the box that reads Warn When Not Saving in ODF or Default Format.
Make existing documents open in LibreOffice
Track down an existing Word/Excel/PowerPoint file on your hard disk and right-click it, then select Get Info. Under the Open With heading in the dialog box that appears, select LibreOffice Vanilla from the list. Then click the Change All button.
Note that you’ll need to do this not only .doc files but also .docx files, and for .xls and .xlsx, and so on.
Change the default word processor font
To switch the default word processor document font to something more modern and business-friendly, like Calibri, open Preferences (Cmd+comma), expand the LibreOffice Writer heading at the left, and then select Basic Fonts (Western). Then change the font to Calibri under the Default heading, at least, although you might also change the other font headings too.