1. The option to display YouTube video is not available in this default slider.
If you want to show video in slider, you can use Cyclone Slider — WordPress Plugins
- Install the plugin and create slider for homepage
- Go to Appearance » Theme Options » Homepage Slider
- Enter your slider shortcode without php tag
Please check the documentation
2. To display YouTube video in “Why Choose Us” section, will need to change some code.
Please send your website URL and WordPress admin login details for temporary at firstname.lastname@example.org so we can make changes in your website.