What is the standard process for building a game? I have used SDLC in the past for creating software, but does the game industry have a standard game development life cycle? I found this: https://www.gamasutra.com/blogs/JuegoStudios/20170413/296019/What_Is_the_Game_Development_Life_Cycle.php. It includes a lot of detail, but is there a game development life cycle out there that can get me to user stories more seamlessly?

This isn't a Game Design question per se. Moving to the Lounge. For more about the project "life cycle," see also http://sloperama.com/advice/lesson10.htm and check out the Extra Credits videos on YouTube - use search string "extra credits video game development"

And if you want to write user stories, just start with your game concept, together with the target audience. Put yourself in the audience's shoes and imagine what you want out of your game. As for Agile, what questions do you have? Ask them in the Production/Management forum.

@Tom Sloper, I do not see the thanks button on this thread so thank you.

I started with a blog, but I'll move the ideas to a wiki-like GDD with your format. As for agile, I will hold those questions for after reading your website.