This is a great reference for comparisons between Outlook and Gmail. - https://gsuite.google.com/learning-center/products/gmail/switch-from-outlook/
How to add an additional account to the Gmail App - https://support.google.com/mail/answer/6078445?hl=en
How to add an additional mail account to the default iPhone mail app - https://support.apple.com/en-us/HT201320
Gmail App information - https://support.google.com/mail/answer/8494?co=GENIE.Platform%3DiOS&hl=en
Google Calendar mobile apps - https://www.google.com/calendar/about/