Find the smallest possible scope that interests you, and pick the simplest tools and gameplay mechanics. I’ve been making my first game in a custom engine forked from CopperCube. The game is a linear first-person shooter with heavy puzzle emphasis. This is way too ambitious as a first project, but I’ve made far more progress with it than my attempts at simpler projects. Passion really does help but you have to balance it with reality as much as you can.