For changing Menus go to Appearance > Menus
For changing other menus settings, go to Theme Options > Footer > Top of Footer > Menu
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
How to change background? You need to edit row under tab Design tab you can find background settings.