Open the app store and search for Outlook or click on this direct link on your device to take you there:
Install the app
Start Outlook and add your e-mail account
If you are prompted to authorize the connection with MFA(Multi-Factor Authentication), authorize the request using the same method you already use for other clients.
If you need to add another account you can do so now
To access other folders than Inbox, click on your user's image at the top left corner
From there, you can also access extra configuration and options by clicking the gear icon at the bottom left corner
