The page slider can be setup from app/js/src/script.js .  In this file you can find the initSlider function which allows you to customize the slider settings:

self.homepageSlider.slick({
  infinite: true,
  arrows: true,
  slidesToShow: 3,
  slidesToScroll: 3,
  responsive: [
  {
    breakpoint: 768,
    settings: {
    slidesToShow: 1,
    slidesToScroll: 1
    }
  }
]
}); 

You can find more settings at http://kenwheeler.github.io/slick/

Each slider item style can be customized from css/scss/_homepage.scss

Also if you want to add more slider items in your homepage, you will have to add a new div which contain the “sh__slider-item” class inside your “sh__sliderky__slider“.