[naet]

Make a very small scope game first. Start with Pong or Breakout or the like, with your own slight twist (can be as simple as adding some unique colors). Keep it so simple that you can easily accomplish it.

Then make a slightly larger scale game, like an infinite runner 2d platformer. Keep the scope small, but try to finish every aspect of it (menu, sound, etc). Once you have a finished version you can decide whether you want to add to it or start another project of slightly larger scope.

Don't jump into it trying to make your dream game. Start with making the game that you can realistically make, and then gradually expand as needed. Once you've fully finished a game you'll have a much better understanding what you can do, what you'll need to learn to do your next project, how much work it was for that scope of project, etc.

Make a game where everything is a solid colored rectangle. Then go back and see what it would take to turn one of those rectangles into a simple animated character. This type of gradual progressing will let you focus on things one at a time, decide your own limits (will I make my own walking animation? or will I use a premade asset? How long will one walk animation take?)