You question doesn't let us know if you already have an email app compatible with Office 365. Best bet is probably to install an app that you know is compatible. Outlook, Nine and some others are specifically designed for Exchange and Office 365. AquaMail, MailDroid and others offer somewhat limited support for Exchange and 365, but have the advantage of also supporting most all email services. A simple search in the Play store will find all these and more.
Setup should be easy. Just follow the prompts and they should walk you through it.
Android since v1.0. Linux user since 2001.