With your Microsoft 365 you can sign in to access apps and documents by going to Office.com. Once signed in you are presented with applications and your recent documents. On the left hand side are app that can be accessed in the browser including Outlook, Word, PowerPoint, and less know ones such as Forms and Sway. Once you sign into Office 365 you are presented with your applications and recent documents. There is also a link to install office to a desktop or laptop. Office 365 apps can be installed to a mobile device by visiting App store of google play. On the left hand side are app that can be accessed in the browser such as Outlook, word, PowerPoint and others.
There is also a link to install office on up to five devices in any combination of PCs, Macs, tablets, and phones; Mobile device install Office by visiting the App store or google play. If you use more than five devices Office will sign you out of devices automatically to stay within the limit.