How does the skill work?
You just say "Alexa, what's happening in Los Angeles today?" or "Alexa, what's happening in Phoenix on the 25th of December?". Alexa then reads out events two at a time and prompts if you want to want to hear more events. You can either say "Go on" if you want to hear about other events or say "Get me details of event 2" to get more details about a particular event like time and place of occurrence. You can get Uber ride details by saying "Get me Uber details for event 1". If you are interested you can actually book an Uber to the event by saying "Book an Uber for event 2".
Where are the events fetched from?
Ticketmaster API's are used to fetch the events.
How is the Uber booked?
Through Uber API's. More information can be found here: https://developer.uber.com/docs