The associated data you are looking for is in related (joined) entities. To access data from related entities, you will need to use the joins between them and can learn about them in the Calendar API Data Elements and Associations article.
To access data from a joined entity you need to add a field to your fields parameter when you make the API call. Add your new field with a name you would like to call the result column followed by a colon, then the dot notation join to the column.
For example, to add a field that is the associated room name for the sectionMeetingInstance add the following to your fields parameter:
Look at the list of joins in the SectionMeetingInstance entity, followed the RoomConfiguration join to the RoomConfiguration entity then followed the Room join from there to the Room entity.
Using this approach you can connect to pretty much any data you need related to the Section or Event entity.