There are a few reasons why your appointments not showing in outlook calendar. One reason could be that you are not viewing the correct calendar. To check this, open Outlook and go to the “View” tab. From here, you can select which calendar you want to view. 

Another reason could be that your appointments are set to “Private.” To check this, open an appointment and go to the “Private” option in the top ribbon. If the box is checked, your appointment will only be visible to you and not to others.