In WordPress Dashboard go to Appearance submenu and click on Customize.
After clicking on customize the theme Customizer page will appear .
Here You have to follow this Path : Go to Customize -> Frontpage Sections -> Call To Action Section
Now scroll down till Title after reaching here you can Add Title , Description , Button Label & Video URL in Call To Action section.
Then click on Publish.
Please follow this Screenshot for Reference :
In WordPress Dashboard go to Appearance submenu and click on Customize.
After clicking on customize the theme Customizer page will appear .
Here You have to follow this Path : Go to Customize -> Frontpage Sections -> Call To Action Section
Now scroll down till Client Image after reaching here you can Add Client Image , Background Image and Manage Image Position in Call To Action Section.
Then click on Publish.
Please follow this Screenshot for Reference :