how to make video game?

Make something really small, like Space Invaders, Pac-Man, etc. I recommend GameMaker or Unity. It will teach you how to program and create or import art assets, as well as a feel for what kind of work goes into even a small game. From there make a slightly larger game, maybe a twist on an existing game. What happens if you need to collect air canisters when below ground in Dig Dug? What if every time you hit the ball in Pong, the paddle gets smaller? This will teach you a lot about game design, and don't be afraid to build off of existing games rather than creating some incredible concept nobody has thought of before. Chances are somebody has, and they found it really tough to pull off. The secret is to finish something and move onto the next and dream just a little bigger.