Welcome to the forum! There is not a lot of cc3 stuff here, but there are some folks around who can answer questions if needed. The best way to get timely responses for general vendor-specific questions, though, is via the vendor's own forums ( https://forum.profantasy.com in this case ).
Please be sure to share your experiences and opinions with the new software here on the forum! Sharing maps is also much appreciated!
As far as how hard it is to grasp, it's very much a state-of-the-art circa early 90s CAD program with a lot of specialized tools to let you draw maps easily. The UI is a single-mode action-object interface, which a bit at odds from the more common object-action interface that you find in most software these days. If you're used to doing things like picking a mode (select, eraser, draw, and so on) and then selecting some objects to work on, cc3 may feel a little alien because you specify an explicit action, pick what items you want to do that action to, and then perform the utterly undiscoverable right-click and "do it" from the popup menu (or enter at the command line). It can be a powerful tool and profantasy has spent a lot of effort to make things easier in the last dozen versions.