First you will need to create a new page, and then select the Frontpage Template from Page Attributes and save it. Then navigate to Settings->Reading and select that page as a static Frontpage.
If you have a stream Shoutcast Stream URL, please add it under CSSIgniter Settings->Music player options (https://prnt.sc/llg6ja)
Once you have the correct template you will need to open Appearance->Customize->Widgets->Frontpage Widgets and start adding your Widgets with your content https://prnt.sc/llg54l
Now In order to have a slideshow, (after you have selected the frontpage/homepage template) navigate to Slideshow->Add New and create a new slide with a featured image (which will serve as the slide image) https://prnt.sc/llg5w1 . Go ahead and create as many slides you wish!
Please have a look at the theme's documentation here http://www.cssigniter.com/docs/chords it has all the info you need to get started with the theme and feel free to contact me anytime in order to setup this theme like you want to.