The Reporting APIs documentation provides some guidance on using the /reports and /topitems endpoints, including examples.  There is also additional documentation on breakdowns and migrating from the 1.4 to 2.0 APIs.  You can use the debugger in Analysis Workspace to see how it uses the 2.0 APIs for...

Hi a.viveros​. We have this on our roadmap and will work to have VRS enabled for the Data Warehouse API.