There are two ways to start using the CityFALCON skill. You can start all of your requests with Alexa, ask CityFALCON to ... and then say the command. For example, you might say Alexa, ask CityFALCON to tell me news about Amazon.
Or, if you don't want to preface every request with Alexa, ask CityFALCON to..., you can launch the skill using the command Alexa, launch CityFALCON. Now you can use the commands without the preface. For example, if you wanted to see which topics are currently trending, you would just say What's trending? When you are finished using the skill, the commands "Stop" or "Exit" will take you out of the CityFALCON program.
While CityFALCON is active, you can still make requests for other skills. Just start your request with "Alexa, ..." and follow up with the command for the other skill. Whenever the task for the other skill is complete, you can continue to make requests directly to CityFALCON.