Navigate to Stars Testimonials -> Add New and insert your testimonials there. Then paste shortcode where you want to display testimonials.

Shortcode

[stars_testimonials]

General Shortcode Attributes

type Choose from grid, slider and masonry
style Choose from 1 to 17
cols Number of columns in a row. From 1 to 12
cats Comma separated Testimonial Categories IDs you want to include
order Choose ASC or DESC
orderby Choose from date, author, title
total How many testimonials you want to display. -1 for all

Color Attributes

stars_color Provide color name or code for stars
text_color Provide color name or code for testimonial contents
bg_color Provide color name or code for background
title_color Provide color name or code for testimonial title
company_color Provide color name or code for company or rank name
arrows_color Provide color name or code for slider arrows

Slider Settings

slidestoshow How many items in a slide at a time. Choose from 1 to 12
slidestoscroll How many items slide at a time. Choose from 1 to 12
speed Speed of slide in ms. Eg: 3000
dots Bottom dots. Set value true or false
arrows Navigation Arrows. Set value true or false
autoplay Auto Play Slides. Set value true or false
autoplayspeed Auto Play Interval in ms. Eg: 2000