Please check whether you have installed and activated “Layer Slider” Plugin.If not, Please go to Dashboard / Appearance / Install Plugins Then Install and Activate Layer slider plugin.
The layerslider export file is already included with the theme package. Please have a look. Please import it via Dashboard -> LayersliderWP -> All Sliders -> Import Sliders.
Then get into the home page and assign the slider under the slider metabox.