Open Outlook for Android. The icon looks like this:

If you haven't already, you can download Outlook for Android from the Google Play Store.

Tap GET STARTED if it's your first time.

Or, got to:

Settings Add Account Add Email Account

Enter your full email address, then tap Continue.

Enter your email account password and tap the right arrow in the bottom right.

Enter a Description for your mail account and tap the tick in the right corner.

Outlook will now log into your account and sync all your mailbox content.