There are specific Categories for the Testimonials called “Testimonial Categories”. You can add a Testimonial Category thru the Dashboard admin menu => Testimonials => Testimonial Categories. Now you can create a new testimonial and attach it to the respective “Testimonial Category”.
You can use the below shortcode to display all the Testimonials under particular Testimonial Category e.g. homepage-testimonials in chronologically reverse order:-
where ‘homepage-testimonials’ (don’t forget the quotes) is the slug of the testimonial category from which you wish to pull the testimonials in reverse chronological order (latest is shown first).