According to the API documentation on Microsoft Azure's website, it says we need to fill in the account name information to work with the API. Currently the documentation shows that it looks like this:
https://<accountname>.restv2.<location>.media.azure.net/api/$metadata?api-version=2.x (where x is a version number)
Do I need to create a Media Services channel first or how do we find the account name for Media Services?
This information is available in the Azure Portal, under the Media Services blade. When you created the account you gave it a name. It will be in the list of Media Services accounts in the portal. Just type "Media Services" in the search box in the portal, and click on the Services->Media Services to see the full list.
In addition, the API Access section of the Media Services account menus will give you the full URL. In the portal click on API Access in the Media Account, and then click on Connect to Media Services with Service Principal to get the connection details for the API endpoint