Use this article to add a Calendar to your Outlook on mobile.
Step 1
Open Outlook on your Phone and select the "Calendar" Tab
Step 2
Select your Profile Picture at the top right and then choose "+"
Step 3
Select the option "Add a Shared Calendar"
Step 4
Enter the Calendar name and choose the "+"
Step 5
Tick the Calendar and untick yours. You are now viewing that calendar.