Hi Thalia! I'm glad you were able to find the Global Address List. I'll go ahead and mark this thread as Answered.
For your users to share their calendars, tasks and others resources among others users on their domain, you will need an Enterprise license.
Here is some more information on sharing resources:
If you'd like, I can get you in contact with our sales team to talk about upgrading, or you can email
sales@smartertools.com for more information.
Hope this helps!