How to start making mobile game

hello i want to start making mobile game with c++ and cocods2dx i want to know how to start and how to use unity ads with this framework and also i want some good tutorial, thanks

Unity Ads does not officially support cocos2d-x (C++).
Therefore, you will need to create your own functionality to bridge native Android/iOS implementations and cocos2d-x.

This requires experience in implementing native Android and iOS applications, as well as extensive experience with cocos2d-x.
If you do not have that experience, you should avoid the option of creating mobile games in cocos2d-x itself.
In many cases, it will be easier to choose Unity as the game engine of choice.

In particular, cocos2d-x (C++) is not well maintained and documented.
Avoid cocos2d-x. This is the best choice for you.

I have been maintaining game apps created in cocos2d-x(C++) for over 5 years and I do not see any future in cocos2d-x(C++).
The official focus is completely on Cocos Creator(JavaScript) and C++ is no longer left out.

If you want to stay with C++, try AXMOL instead.