Check out the user guide and let us know a little more about the shot you are trying to analyze. Make sure your system meets the minimum system requirements to run After Effects. Even the format of the original footage can cause problems. A simple camera pan must be identified as a camera pan in the Camera Tracker, and shots with little or no fixed geometry in the scene are very difficult to analyze. The other thing that could be causing a hang in analyzing the scene is a shot that will not camera track. so i was suppose to track the footage below but i saw a lot on YouTube about on the Effects Control on the 3D Camera Tracker effects that there was a status (Initializing, Percentage to be done) beside Cancel, mine doesn't have Status (even in CC 2017). There are almost as many amateur tutorials with bad advice as there are good ones. I'm not yet fluent in English but i hope you understand to figure this bug out.
It is very important that you figure out if the folks doing the tutorials are experienced users. If you found the tutorial you are watching by just doing a search of the internet you may be watching a poorly done tutorial by an amateur. If you are new to After Effects I would strongly suggest that you take some time to take a look at the user guide and some tutorials that you can find by typing Camera Tracking in the Search Help field in the top right corner of After Effects.
Without knowing a lot more about your workflow it's pretty hard to figure out what is going on in your project.
ADOBE AFTER EFFECTS CC 2018 3D FLAG MOVIE
That will work if the comp contains a movie and no other elements that the tracker would interpret as elements in the scene. You are Camera Tracking a comp, not a movie.