As you may be aware the price for Microsoft Office has increased. If you are a home user and do not need Office 365 there are other alternatives for free. They offer the vast majority of functions that Microsoft provide. To be honest they provide in my opinion everything a home user usually requires.
If you already have Microsoft Office on you PC (which is usually the case as it comes pre-installed with most new machines) you can remove it or just leave it and install an alternate Office package.
LibreOffice.
This is what is called open-source software. It is totally free. If you have a business you can still use it for free. I think it is one of the best alternatives to Microsoft Office 365. It does not include an email program though. That said there a plenty of alternatives to Classic Outlook. LibreOffice can open and save .docx (word), .xlsx (excel), ppt (PowerPoint). You can down load Libre Office at the link below.
OpenOffice.
Open Office like Libre Office is open source and is totally free. It can do the same as Libre Office. It is not as polished as Libre and is no longer being developed. It can be downloaded at the link below.
WPS Office for Windows.
WPS is totally free. It does have some advertising. It supports all formats of Microsoft Office files and has 1Gb of free online cloud storage. WPS is also available on iOS (iPhone) and Android) which means you can use the cloud storage to share your files between devices. It can be downloaded at the link below.