A family of Microsoft word processing software products for creating web, email, and print documents.
Contact the institution that is the owner to find if their license includes desktop editions of Office. If it does, ask them how to download the programs.
For Office programs, I have to stay signed in to one account, the one assigned by Microsoft. But to access online storage on OneDrive and/or SharePoint, you should be able to sign in and out to access different cloud storage.