Hi,
Try this in Custom CSS.
.page-id-2 is the page’s id, if the page id is 2 then use this, if the page id is 100 then use it like this .page-id-100
If you don’t know how to find the page ID, click Edit that page, and in the URL you will find the Page ID, like this..

.page-id-2 #top-bar, .page-id-2 #header-section, .page-id-2 #mini-header, .page-id-2 #footer{
display: none;
}
If you don’t want copyright, then use this..
.page-id-2 #top-bar, .page-id-2 #header-section, .page-id-2 #mini-header, .page-id-2 #footer, .page-id-2 #copyright{
display: none;
}