I decided to go for kotlin as my first language because I had ideas for a mobile app. I quickly learned that android dev isn’t the best starting point, and I’m not a fan of the lack of choice I have for editors with it. I only really know some basics, I used to know some javascript but forgot it
You can just use the Kotlin compiler, or separate some scratch files in your Android Studio project. There’s nothing wrong with learning Kotlin, but learning Android development is using the whole toolbox at a beginner level.
The Kotlin compiler can be run from the command line. Doing it that way might separate your concerns.
Have you looked at using Compose? Philip Lackner has some easy tutorials to follow. It takes some of the major development hurdles out of your way.