There are two ways to add a slider, either using basic sliders that are created within your Theme Options under Slider Setting. Once you create a slider using this method, it will appear in a Slider block in the page builder.
Here is a quick guide for it: http://docs.creiden.com/circleflip/theme-options-2/sliders-settings-2/
The second way is to use Revolution Slider which is bundled with the theme. This will be added using a shortcode block by copying the slider shortcode into the block.
Here is the plugin documentation as well for you to help : http://www.themepunch.com/revslider-doc/welcome-slider-revolution/
Let me know if you have any other issue and I will be glad to help.