The App is separated into individual reports, with each report having multiple pages within it. Access to the list of reports contained in the App can be gained by clicking on the >> , located below the Power BI logo in the top left.

This will open list of reports along the left hand side of the screen.

In order to view pages of each individual report, click on the downward arrow against that report and select the page you would like to view.

Please feel free to review the Landscape User Guide General Functionality presentation slides, which look at the  navigation and tools in more detail.

For more information about navigating PowerBI Reports, please visit:

https://docs.microsoft.com/en-us/power-bi/consumer/end-user-report-open