Hrm... I suppose I spent 15 years making other people's games first. >_< More seriously, just start with small stuff. Make a simple 2D game with a something like the Love framework or Pico8. Then try to scale up a bit or use something a bit more powerful. If you are really want to make a game solo, then the best thing you can do is learn to control your scope. You'll never be able to be good at every part of making games, so figure out what parts you want to work on and figure out how to make a game around those skills.

You also don't have to make do it alone. You can hire out art, programming, sound, music, writing... really anything. Most "solo" devs do that to some extent. Also try and seek out your local gamedev community. Asking online is fine, but you'll get more out of an in person conversation with someone who's done it before.

Lastly, game jams. There are smaller game jams going on all the time, but the big one is the global game jam in January. I've always liked that one because there are always new people. In my experience, fresh gamedevs are always perfectly welcome. You'll have someone else on the team that can rough out the structure for you, then you just need to apply what you already know as a software developer to fill in some blanks. People also like to do role bending at jams too. Programmers will try making art, artists will try making music, and sound people will try programming. Jam games are usually bad, so nobody will expect anything you make to be any good, but people generally have a blast doing it anyway. :) I like to rope people into making NES games every year because even as experienced game devs they are so sure they can't write C code, let alone for something 40 years old, certainly not in 48 hours! They do just fine once they dig in. :D -> https://www.slembcke.net/nes/