Good questions - in excellent English!

First, be aware that the primary purpose of Vue is to create natural outdoor environments. Vue has almost no model-building ability, so you must either use another program for 3D model-building or rely on purchases of models and free models. (This includes characters - you cannot build characters in Vue.)

City Engine is more advanced than you need. If you are interested in obtaining buildings, consider Sketchup (you will need a version of Vue that allows you to import models in the *.obj file formats at a minimum). If you wish to build your own buildings, Sketchup also is an excellent choice for a beginner. Truespace is another excellent free 3d model-building program that would allow you to make your own models of buildings, and of organic objects.