Learn game scripting

which language you prefer for gaming if you want to develop game in C++
then go to Microsoft virtual academy is good platform training is being given by the experts free of cost and a completion certificate too from Microsoft
 
Your question is not very specific. Do you want to learn how to add functionality to games which allow this (i.e. mods)? Or do you want to learn how to develop a game your own?

For the first question there is no general answers. It all depends on the specific game and its support for modding. For the second question however I would recommend to take a look at Unity (http://unity3d.com). This is a very powerfull game engine which itself is free (except for the Pro version) and has free licensing options (if you did earn less than 100.000$ in the last year).
It also got very good tutorials for beginners, intermediate and advanced developers.