By default, the engine comes with a project where you can run around, jump, shoot, change renderer settings, and even teleport to a different scene.
You can use it as a starting point to learn about using the engine.
Note
IBL is disabled by default to reduce gpu memory usage. That's why in-game IBL switch won't work. Enabling IBL will fix it. (Eagle/Sandbox/Content/Textures/IBL/limpopo_golf_course_4k.hdr)
Note
If you can't run demo project because of lack of GPU memory, open Eagle/Sandbox/Engine/EditorDefault.ini file,
and set TranslucentShadows to false, and also set Volumetric Light Settings -> bEnable to false.
You can additionally try to reduce resolution of shadow maps.
Demo project
Demo runtime