As you’re just getting started with building android apps and I assume that you’ve set up everything like setting up the Android Studio IDE, downloading the SDKs and creating a brand new project. You can find a lot of tutorials and videos on how to do these boring things on the internet, let me skip that part.
Tutorial on setting up Android Studio | Official Documentation (https://developer.android.com/studio/install)
Now, that you have a brand new android studio project, let’s start exploring the IDE a bit. On the left side of the IDE, you should see something like