RBGL's API is the same as RB3D's — you should be able to use RB's language reference to glean what each equivalent function is. The primary difference is the addition of the prefix RB3D to each of the function names. But why not use RB3D itself?
Neither RBGL or RB3D builds spheres (or any other shapes, for that matter) for you automatically — you'll have to build that yourself. For RB3D, you can load in a pre-built 3DMF model from a 3D modeler like Meshwork (
http://codenautics.com/meshwork/). Meshwork can easily build a sphere for you.
As to moving a camera, things get more complicated. Depending on how you position/rotate/zoom your camera, it's going take a bit of math to get the camera where you want it. Joe Strout's 3D FAQ at
http://www.strout.net/info/coding/rb/ has some code for orbiting and aiming a camera.