How do I open AVD Manager?

SDK Build Tools are not installed If it fails then you may have to install it again. You look at the build tab at the bottom of the screen, it will display the error message and option to install the Build tools. Install it and you should be able to see the AVD Manager. Another way is to go to the SDK Manager.

To start the Android Emulator and run an app in your project:

In Android Studio: select Tools > Android > AVD Manager , or click the AVD Manager icon in the toolbar.