I’m new to Kotlin and starting from watching Kotlin courses in coursera. What should I do after the courses to learn the language better? Are there any websites (what can upload and check your code) with tasks on programming in Kotlin? Or what is the best way to get practical skills in programming?
It is the same idea with any language. You start a project of your own and work on it. If you want not only to learn, but also to make something valuable, you can contribute to an opensource project.