Hello;

Do these:

1 – Make images with your graphics software with these details: width=998px , height=380px and no transparent if you save it in png format.
2- Add or insert the code below to this file :
catalog/view/theme/shoppica2/stylesheet/screen.css.php
or to the Styles tab in shoppica controle panel (go : Extensions -> Modules -> Shoppica 2 CP then Design-> Styles and put the code here and save).

#image_intro {
  padding: 0;
  margin-top: -30px;
 margin-left: 0;
}

#image_intro_preview {
  padding: 0;
  margin: 0;
  width: 998px;
}

#image_intro_preview .s_button_next_holder,
#image_intro_preview .s_button_prev_holder
{
  margin: 0 40px;
 }

3- For the “Image settings” in the "Intro" tab, disable "Put border on image"

Note; this is only for the home slide not for the products slide.

Good luck

Sam