How do you make a video game

You need many things.

First you need a video game engine.

Then you need programming. which is what makes that game do what it does.

then you need art. that is all the visual stuff like the levels, 3d models, characters, ect.

If you want to learn how to make a game and not have to learn all three of these fields i suggest getting involved in the modding community.
RPG Maker is a series of games available for the SNES which allows you to create simple JRPG-style games, but it's very difficult to find these days.