You can use Alexa to get a ride using popular ride-sharing apps Uber and Lyft. To use Alexa for either of these services you need to add the Uber Alexa skill or the Lyft Alexa skill.
With the Uber Alexa skill you can choose the type of Uber you want and it will send a request to your default pickup location. You cannot enter a destination on Uber using the Alexa skill.
While using the Lyft Alexa skill you can give more information, but it is still more limited than the app. Once you set your home and work destinations you can pass that information to the driver, but you cannot add other destinations. It is possible to see where your driver is and see how long a ride will take, but that is about it.