In the description of the Example it says:
“Learn how to construct a detailed level…” and so on…
My Question is: Should i explore this by myself or are there any other helpers, tuts or a more detailed documentation?(Except thisone)
Thx 
Besides the one document you posted, there is inside the code with alot of comments.
However, you will need to read the comments around the functions through your own navigation… thats it. =)
This tutorial on adding in a third person functionality was helpful to me to get in and start working with C++ on Unreal. There are many “answers” where people discuss this tutorial if I recall, those cover bringing the tutorial up to date as it it doesn’t match the current UE4 rev. It’s not at the level of constructing a detailed level, just manipulating the code, but possibly still useful in getting your feet wet so (as Devero says) you can start reading the code and learning.
There is one other minor tutorial on it in the Wiki under the S category.