Hello,
In case you want to be able to edit responsive settings of the slider then we would recommend you to use the Revolution slider and follow the documentation https://www.sliderrevolution.com/faq/responsive-content/
We have imported an example of the revolution slider for you, so you can replace existing content by your own according to your needs.
To add it on the home page just edit the page and add the Revolution slider element.
If you use slider image as the background image then you need large-resolution images that will fit the slider width, in other case image will be scaled to cover the width of the slider.
Regards