As others have said, OpenOffice Writer and Calc are every bit as good as Word and Excel:
https://www.openoffice.org/
(It can help to get them to automatically save in Microsoft formats though, so that people you email files to can access them in Microsoft Office programs. Easy instructions here:
http://helpdeskgeek.com/office-tips/set-openof%EF%AC%81ce-org-to-save-in-microsoft-of%EF%AC%81ce-format-by-default/ )
For DTP, Scribus is superb
https://www.scribus.net/
but, because it offers so much, it's got quite a steep learning curve.
Serif PagePlus SE is far more intuitive. It's now been retired from the Serif website but you can still download it from here:
http://www.softpedia.com/get/Multimedia/Graphic/Graphic-Editors/Serif-PagePlus-SE.shtml
(After clicking 'Download', click on 'Softpedia Mirror (US)')
If you need an activation key for it, use this one:
PLX7U-SER01-11922-28148-12864