@Duoas
Personally I picked most of the basics of it up from this book here.
http://www.amazon.com/gp/product/B00CITNP8A?btkr=1
It is mainly one of those books that goes through creating a bunch of little game examples and doesn't really go into that much detail on what everything does. But it did help me figure out how to structure a game with the framework and after I had that basic knowledge I was able to figure out how everything worked by reading through the documentation and just testing things out.
Though if you do get that book I should say that it uses code that is deprecated now that 3.X is out, but it is pretty easy to figure out what to use instead by looking at
http://www.cocos2d-x.org/reference/native-cpp/V3.0alpha0/da/d58/deprecated.html and also most of the source code of the deprecated stuff shows what to use instead in the comments. It also doesn't really use good C++ code but that can also be changed also I got mainly just to see how to structure a game with the framework.
Other then that I am not really sure about free resource like tutorials that are available since I haven't really looked for them :(.
Though here is a github of one of the projects I created with it if you want to have a look. All the platform independent code will be in the Classes folder and all the platform specific code will be in Win32 folder.
https://github.com/bjumbeck/SkyDefense . The repo only hosts the win32 version of the game but it is coded in a way that it can easily support the mobile platforms just by adding a few platform specific stuff.
It is mainly just quick and dirty code and I mainly put everything in a single class GameScene.hpp but should give a decent idea of how a game can be structured with the framework. I included everything including the libs in the projects so may take a bit to download but should compile and run on windows VS2013 right of the bat if you have that.
But anyways hopefully that can help a bit since yeah it is kind of a hard framework to learn in the beginning since it is kinda big.