3d art/3d modelling tool software tutorials?

Hello, I am a hobbyist trying to learn how 3d art software such as blender and maya were made, to try and create my own as a learning project, but one thing has been locating tutorials that are about making a tool and not a game, especially when it gets complicated trying to break down the tutorial for my own project without much explanation. Are there tutorials geared towards making a software, or even game or general tutorials that give a lot of explanation so that you can easily take parts and use them in your own project?