Sparkling menu, head and dashboard and other WordPress basics

Hello i need your help with couple of things, im using Sparkling them, i want to have the design exactly as i saw it in the demo, but when i refresh to see how is looking the web site the first thing is that the menu appears under the head picture and i want it topping the pictures as i saw it on the demo, second thing is even uploading the head picture as big as 1900x 550 still when i published doesn’t appear in the full size, always appears kind of grey borders something that is very ugly.

also i was checking how to change very basic things like in the dashboard- appearance- header to change my logo but it always send me to the theme customize which is really annoying cause from them i can’t change so many things that i can really customized from the dashboard

Somebody can help please, i really like this them but i need to fix this things as soon as possible my client needs it very fast.

The best place to start is by reading theme documentation.

Slider is not the same thing as Custom Header image. On our theme demo I am using featured slider and Custom Header image is not enabled at all. Custom Header is used for logo and logo only. Custom Header no longer has its own dedicated page and since WordPress 4.1 is is moved to WordPress Customizer and there is nothing you can do about it. However all options are still there but looks different. You will have to get used to it.

Slider can be enabled via Appearance >> Theme Options >> Main >> “Check if you want to enable slider”.
Slider uses featured images from posts that you want to display inside slider. It can be any number of posts with featured images.

Let me know if this helps.