The Geometry starter quiz is no longer built into the app, and the full Geometry course is no longer shipped with it either — this app is a container, and it arrives empty on purpose.
What it does ship is Circle Geometry: six short, assignable quizzes with figures, where every wrong answer is explained by the misconception behind it. It is meant as a model for a library of your own rather than a course to work through.
To import it: open the homepage, choose ↓ Import, and pick the file.