In previous versions, there were built-in reports from the main 3CX interface. Now that reporting has gotten bigger and better, was moved to a separate program. Under Programs | 3CX Phone System, you will see a 3CX Log Reporter utility.
Run this program, and you will have a menu of choices based on what type of reports you'd like to have:
Ring group statistics
Run the reports that you like. Some of them should be viewed daily, some weekly, and some monthly. Statistics report is one of the daily reports to check out. This will help you determine if you have any issues to tackle. Others, like the abandoned calls, might also be helpful on a daily or weekly basis. Queues, Agents, and Ring groups will only be helpful if you use those features. I'd suggest looking at each one to see what is offered.