This applies to version 14 of your PBX GUI
User Control Panel in PBX 14 is a completely revamped interface from UCP in PBX 13. Taking the core elements from UCP in PBX 13 and then adding multiple dashboards and resizable widgets functionality allows users to completely customize the look and feel of the User Control Panel.
If you'd like to learn how to develop your own modules for UCP 14 please see: Developing for UCP 14+
You create users and manage their permissions inside the User Management module in FreePBX