Jetpack Compose is Android's modern toolkit for building user interfaces. Instead of describing screens in XML, you write them in Kotlin as composable functions: small, reusable pieces of UI that you combine into whole screens.
Begin with the basics: composables and modifiers, then the layout building blocks Column, Row, and Box. From there, learn how state drives the screen, so that when your data changes the UI updates on its own. Lists with LazyColumn and styling with Material 3 theming round out what you need for real screens.
The lessons below are longer courses that cover the basics and go further, so you can stop once you're comfortable and come back for the rest later. Start with the first one, then continue on to App Architecture.
Philipp Lackner teaches Jetpack Compose from the very beginning, enough to build basic UIs. A good first stop if you are new to Compose.
A complete Jetpack Compose course for Android developers, aimed at both beginners and people with some experience.
A zero-to-hero Android development course built around Jetpack Compose, designed for complete beginners.