a question need answer please

please i have a question and i need an answer .. i want to make a game and idk how i want to know how do i start ?? the game idea is in my mind but i dont know what i do write it or what !! please need answer

You have to learn a few languages to first make little programs, after several years you can try to write little games. A game is not easy to write, it takes about 2-3 years for a little indie team to write a game.
You should definetly read a few articles and tutorials in the internet about the languages to write in, etc.

It would depend on which language you will want to code it, as well, which graphic engine you will use (CryEngine, Unreal Engine, etc...) the first thing for you to learn is to code, but not simple coding, instead in-depth programming, packet structures, security(in case of an online game) and so on; as stated on the previous post, making a game is not as simple as many people would believe.