How To change default favicon icon image
Method One:
Replace favicon.ico image present in theme folder with your own favicon image.
Make sure, name of image is favicon.ico
Method One:
Navigate to:
Home Administration Appearance Appearance settings
example.com/admin/appearance/settings/tara
Here you can upload new favicon image.
How to create custom favicon icon
There are many free tools to create custom favicon icons and convert your image into a favicon icon, like: www.favicon-generator.org