First you need to install Android Studio on your machine. Then simply follow these steps.
Go to you navigation bar and open Android Studio.
From the toolbar open AVD Manager. (If you cannot see it create a new android project)
Create a Virtual Device.
Select a hardware device that you want to install your app.
Select an android image that you want to install on your device. (If you cannot see any images you can download the require image from Recommended, x86 Images or Other images)
Add a name to your AVD.
Now the virtual device has been created and you can simply run it by clicking the play button.
Now you have setup the virtual device and now you need to install the APK file.
Download the APK file that you want to install and Drag and Drop it to the emulator.
The APK file has been successfully installed and you can see it in your applications.