The easiest way to use your 365 email and calendar on your smart phone is to download the Outlook App:
Google / Android - https://play.google.com/store/apps/details?id=com.microsoft.office.outlook&hl=en_CA
Apple / iPhone - https://apps.apple.com/ca/app/microsoft-outlook/id951937596
Once this app is downloaded on your phone, just login using your 365 account.