Or in your site front page, in the admin bar find Edit Page ( Back-end Editor ) or Edit with WPBakery Page Builder ( Front-end Editor )
For changing size and margin, go to Theme Options > Header > Top of Header > Logo element
For disabling slider or changing it with other title types
Example Breadcrumbs or Title, Go to Page Edit > Page Settings > Title Type
For overall website title type go to Theme Options > Title & Bredcrumbs
You can edit icon, text, typography, colors and margins inside of this element edit box in page builder.
Instead Quick Contact also you can create any page and assign it.
In widgets find Footer 1 sidebar area and edit it.
For changing background of Footer, Go to Theme Options > Footer > Footer Widgets > Container Style Kit
This Footer has “Fixed footer under body ?” option On, if you want to turn it Off go to Theme Options > Footer > More
You can edit row under tab General find Parallax image and replace, add or remove it.
You can edit Title, Background Image, typography, colors, margins and … inside of this element edit box in page builder.
For editing menu navigation settings go to Theme Options > Header > Top of Header > Menu Element
And for styling menus go to Theme Options > Header > Top of Header > Menu Styles of this Row