In WordPress Dashboard go to the Appearance submenu and click on Customize.
After clicking on customize you will in theme Customizer.
Here you have to click on the Home Page Section.
Here you have to click on Testimonial Section
In Testimonial Section Here you can Title & Description also hide/Show.
Go to Customize ->Frontpage Section-> Testimonial Section -> Title & Description
In WordPress Dashboard go to the Appearance submenu and click on Customize.
After clicking on customize you will in theme Customizer.
Here you have to click on the Home Page Section.
Here you have to click on Testimonial Section
In Testimonial Section Here you can manage content.
Go to Customize ->Frontpage Section-> Testimonial Section -> Content