I work as a game developer & designer and currently am employed as director of engineers - the most important thing when it comes to creating a game, is the management thereof-. There are a lot of great programs out there that can help you. For smaller businesses something like Trello would suffice, however I prefer working with more complex programs such as ClickUp for my management side of it all. It allows you to properly track everyone's sprints and tasks while maintaining a broader timeline etc. It has built in Gantt charts and more, whiteboards and so forth.
Of course one would need to begin first with the concept of what the game is meant to be, what it's gameplay structure looks like, the goals users are meant to be achieving. From there assign the correct teams from sound design, visuals, art design and other assets. It's honestly not that hard to get started as long as you have a good set amount of goals - and always adhere to due dates.