If you create or add calendars to your Google Calendar but they do not show or give you an option to show on your phone, go to the following link and make sure that the calendar you want on your phone has a check mark next to it.
Step 1: Log into your Google account on a computer (not your phone).
Step 2: Go to this link. https://www.google.com/calendar/syncselect
Step 3: Make sure there is a check in the box next to the calendar you would like to see on your phone.
Step 4: Click Save in the bottom right corner
Step 5: Check the calendars on your phone and the missing calendar should be available to select and add.