Office 365 on the web works well on Linux if that has enough functionality for you. If not, the only way to get a modern version of the real Microsoft Office is in a VM. Older versions will run over Wine.
As far as alternatives go, OnlyOffice has the best reputation for file compatibility. I use LibreOffice and am very happy with it.
Avoid OpenOffice. It is really just an ancient version of LibreOffice.