To update the hero section in Shane Jekyll Theme, open _data/site_data.yml file.
You will find the following code there,

testimonials:
  shane_section: Testimonials
  title: What clients say about my portfolio template
  carousel:
    - name: Justin Bieber
      designation: Photographer
      img_src: "/assets/img/about/1.jpg"
      testimonial:
        "We were looking for a logo with a touch of modernism. Arlo grasped our needs
        and produced a stunning design. Awesome to work with Arlo. Incredibly
        organized, easy to communicate with, responsive with next iterations."

    - name: Teodor Federico
      designation: Freelancer
      img_src: "/assets/img/about/2.jpg"
      testimonial:
        "I purchased the theme a few weeks ago. I had some issues with the theme, I
        asked customer support to help me with and they were helpful and kind to
        help me with all my problems. I definitely recommend this theme to everyone."

    - name: Bauen Fernandes
      designation: Web Developer
      img_src: "/assets/img/about/3.jpg"
      testimonial:
        "We were looking for a logo with a touch of modernism. Arlo grasped our needs
        and produced a stunning design. Awesome to work with Arlo. Incredibly
        organized, easy to communicate with, responsive with next iterations."

shane_section : That is used for the section title badge
title: That is the section title
name : Testimonial author name
designation : Testimonial author sub heading
img_src : Testimonial author photo
testimonial : Content for the testimonial text