There are millions of articles and videos on YouTube, tutorials, and threads on this forum on this topic. Basically:
1. Decide on the game's plot and gameplay. Will it be management or a visual novel? Maybe a 3D RPG? Or a 2D RPG? There's a specific game engine for each of the genres I mentioned, you can choose any. If you are looking for a visual novel, go for Renpy. 2D RPG - rpg maker and so on. Of course, you can create management in Renpy or 2D RPG in Unity, it's up to you. Choose a game engine and learn programming.
2. Decide on the graphical component. Again, it all depends on the game and the game engine you choose. Basically, for most games on this forum uses DAZ 3D. It's easy to get started, there are a lot of tutorial videos and youtube channels on this program. You will need a lot of time and hard work to achieve a good render. If you want or can, draw by hand by yourself in photoshop or other graphic editors, but it takes talent.
3. Work. Work. Work. It's going to take a long time.
This is the most simplified interpretation of everything you have to do before you reach the release point of the game. Of course, this can all vary depending on your preferences and the genre/history/gameplay of your game. Use google and learn as much as you can about making video games. It's a very challenging job. If this is your first game, here's my advice: don't think about making money and start small. Focus on the path and the skills you'll need to improve, not the fact that you can make money. If you really commit to it and work hard, everything will come with time.
That's what I can say about it. I'm sure - more knowledgeable and experienced people can correct me or tell more than me, but that's my 2 cents.
