This scoped storage tutorial explains the basics devs need to know to access and write files in Android 10 upward.

If you're new to Android Studio, start here: Part 1 walks through installing Android Studio 3.x and launching your first Android project ...

Now, in Part 2, you’ll code your first app. The animated mobile app consists of a single activity, which presents Google’s Android robot character and a button for animating the character.

With IO around the corner, it's a good time to take a look at Google's cross-platform mobile development platform - on Android Studio and on Visual Studio Code.