1. From your dashboard, go to the Appearance > Customize >Homepage sections >Testimonial 


2. Now check the checkbox to show the section


3. Now add the Title, Subtitle, and Text in fields


4. Now click on the Add New Field 


5. Now add the Title, Subtitle, Description, and Image in fields


6. Now click the on delete item to delete the Item


7. Now Remove/Change Image in the Background


8. Hit on the Publish



See Live Preview:-