Shared Calendar Setup

i need help setting up a shared calendar.
i have successfully created numerous calendars on the server.
i have (i think) shared the calendars with both groups and users.
i can create a new internet account on my os x majove system and it connects immediately to the server whether i am logged in as admin or a defined user. however, when i attempt to access the calendar using mac calendar i can only see the calendar information only if i am logged in as admin - not as a defined user.
when logged in as someone other than admin, i can make the connection to the server calendar (on a mac - system preferences > internet accounts), but when I launch the calendar app it shows the connected server but no calendars. i displays a warning icon that has a HTTP 404 error message suggesting the the URL is incorrect.
I assume this is a problem with the way i setup the calendar or the users or the method i used for sharing the calendar.
can someone point me in the right direction?