For editing or removing Back to Top or Quick Contact items go to Theme Options > Footer > More
Instead Quick Contact also you can create any page and assign it.
For changing Copyright text go to Theme Options > Footer > Bottom of Footer > Icon and Text Element
In widgets find Footer 1 to Footer 4 sidebar area sections and edit them.
For changing background of Footer, Go to Theme Options > Footer > Footer Widgets > Container Style Kit
This is Image element, you can find it in Page Builder and edit it with ease.