Everything you need is at massgrave.dev, the site provides genuine installation media and clear instructions. If you can read, you’ll be just fine.
For most people, you’re looking for the Office C2R Installers, scroll down to the link tables. You’ll find a table for every language and every version, start by finding your preferred language, though you can always add more languages later.
Office 365 is the best version, there are different product packages each containing a set of Office programs, the one with the heart next to the download link is probably what you need, it’s an online installer that will install the 365ProPlusRetail package which contains most of the Office suite programs, if you’re missing a program or you want fewer programs just find the version that suits you most and install it,
You can use the offline installer if you want to deploy MS Office on multiple machines , so you only have to download it once, or if the online installer isn’t working.
For Windows 8.1 and 7 use the offline installer to install Office 2016, as newer versions of MS Office are not supported on these operating systems
If you need a more customized install beyond the C2R installers you’ll have to use the Office Deployment Tool (ODT), there is a great guide on gravesoft.dev too.
if you get an error during installation, follow the instructions to delete your old version of Office using the Office scrubber script on the same page
All of the popular activation methods are very conveniently bundled in the Microsoft Activation Scripts (MAS) activator.
Just open PowerShell, copy and paste the command and click enter, you’ll be prompted to select an activation method. Generally, for Windows 8 and above, use Ohook, once its installed you can click any button and your product is permanently activated.
For Windows 7 and older versions of Office you’ll have to use OnlineKMS. for more info about the differences between these methods check the comparison chart.
Follow the instructions on massgrave.dev,they are very idiot proof.
Pick your MacOS version, download the product and activator .pkg files, and install them, if it doesn’t work, clean everything with the office reset tool and install again.
If you want to add more language packs refer to Microsoft’s Guide
MS Office isn’t supported on linux, if you need an office suite, use an alternative like LibreOffice or OnlyOffice.
If you really have to use MS Office then i would try the web version of Office 365 first, If they don’t work well enough for you, you can look into this GitHub gist by eylenbug.
Or just dual-boot Windows and save yourself the headache.