Yes Mario, you really should slow down and look at the instructions that have been given to you. Look at the differences between your screenshot and Karl's. There are many differences, one of the most important is that you have the wrong Projection Type!
You need to look from the side as Karl said, not from the top. Also look in the 3D Window, is that how it should look when you place it in the floor plan? If not, you need to set a parallel projection until it does.
With three pages of help from ArchiCAD pros ,you've gotta start wondering where it's all falling down.
Cheers,
Link.