If you're just starting out with developing, you probably can't imagine how long a certain idea will take to make. This is the reason I'd recommend getting into Challenges like programming a game in a week. This will make you think about the easiest type of game you can possibly make with your skills. Many people(in game developement) therefore start with apps for chaalenges, as a phone app can just be controlled with one Input(touching the screen anywhere) and still be challenging.
So here are some examples of challenges you could try as a developer.
1. The One Butoon Challenge
-You are just allowed to give one type of input like touching a screen or the spacebar
2. The One Week Challenge
-You have one week to programm a full game
3. The Static Screen Challenge
-The game isn't allowed to have camera movement and therefore everything is kept in a small area
4. The Object Limit Challenge
-The game is only allowed to have a certain ammount of different object and therefore has content restrictions
5. Theme based Challenge
-The game has to be based on a certain theme like small planets(often used in game jams)
Hopefully this could help you making smaller games in the beginning of your time as a programmer and that you can now start building a working project.