BeTheme have many different sliders included and you can use them as Muffin Builder item or shortcode. One of them is a simple SLIDER you can see on https://themes.muffingroup.com/be/theme/shortcodes/content-blocks/#slider and it has several different layouts you can choose from.
This item could be used within Muffin Builder or as raw shortcode. However, to make this Slider visible for visitors, you have to add items (images) first. To do this, please go to Slides > Add new section.
All you have to do here is: set Featured Image, Link, Target and add a Description. You can also set category for each slide and its order and later, under Slider item settings, you can display slides from specific category or order them by Date, Menu Order or Title.
If you do not see the Slides in main WordPress dashboard, please check Betheme > Theme Options > Global > Advanced > Theme Functions if this custom post type, has not been disabled.