Hello, @dGOvile,
Please first watch this video: https://streamable.com/8euwk8 As you can see in the video the header and footer appear fine, now please check back to your site after clearing the browser cache.
For the sticky header issue simply go to the Dashboard >> XStore >> Theme Options >> Theme Custom CSS and then paste the below code there
.sticky-on .header-bottom{background:black !important; color:white !important;}
Then save settings your issue will be resolved.
Regards 8Themes Team.