Hello Guys, I am 14 years old. I had been playing games since many years and i want to become a video game developer when i grow up. For now i wanted to create a 3d game. I am a completely beginner and i need some advice about how to create a game? Which Game Engine Should i use? Which programming language or scripting language should i learn?.

Thanks in advance!

You should check out the FAQ.

That should get you started, and you can ask more specific questions after :)

Do not make a 3D Game to begin with, you will miss out on major fundamentals and basic 2d Development.
Start small.
Weather or not you use an engine like RPG Maker or code using a Lang. Like Python is irrelevant.
Start small.
Make a small 2D clone game, like Pong, or something of the like.
Or if you want to code, create a "Hello World"
Starting big and fancy and in 3D as a complete beginner will burn you out, trust me.
Start small.

Which Game Engine Should i use?

RPG Maker and Game Maker are good Engines for 2D Creation as a beginner. Unity for 3D

Which programming language or scripting language should i learn?.

I'd Recommend Python or C# [C Sharp] as a first coding lang. for a beginner.

When you do bust into 3D Dev, however, I recommend Unity for your engine, if you go that route. There are many assets to use, lots of support and a great community.
Good luck.

Starting big and fancy and in 3D as a complete beginner will burn you out, trust me.

If by starting something 3D you mean coding the 3D rendering engine from the ground up, I agree with you. But if we consider that building a complex 2D game is much harder than a simple 3D game (which btw can be done with kodu game lab or similar), 3D or 2D would not make that much difference. The important thing is to do what is necessary to get simple games running.

A complete beginner should avoid trying to do things "from the ground up", thus making Unity3D, Game Maker or any alternatives a good start point.

There are also some free (really free, not free*) alternatives as well, such as GameDevelop.

You may also want to learn how to make computer programming, so that you can create much computer..

But joking aside, if you are looking for a computer language to start out with, I would highly reccomend that you start out with c#, since it is a very easy language to learn at first, and is used by Unity. I would also reccommend c++, however it is a fairly advanced language, and wouldn't get you very close to creating your first game, but it would help you in learning how to create games using more advanced engines, or writing your own engine, in the future. It is also the language that most people start out with, since it makes it easier to learn other languages due to it's difficulty.

If you want my story, I started out with GameMaker, since it used drag and drop, and didn't need that much coding. I got to learn a lot of gaming fundamentals, and learned a lot of algorithms. I later moved on to Flash, then learned c++, then learned c#, etc...