Looking at your site, the slider is full screen, in that it fills the whole of the screen as intended.
However if you want to hide the footer on the home page only, add this in Customize > Additional CSS:
.home footer {
display: none !important;
}
#home-slider-section {
margin-bottom: 0;
}the first part will hide the footer, and the second part makes sure there is no padding below the slider.