When first launching the application, you will be presented with the option to 'Create New Vision'. Click this button to get started, and launch the immersive space. You will need to grant access to hand tracking, and scene tracking your first time launching the application.
Pinch your right index finger + right thumb tip together to create a new shape. Drag over to increase the shape width, and drag upwards to increase the shape height. The shape is completed once you release the pinch gesture.
You can see your current tool settings on 'Tool Settings' panel. This will change the default settings for all newly added shapes. Change your current shape, material, color, or add a PhysicsBody.