Please help with menu

Hi, can’t understand how to make a menu like in

In my project - it looks very bad.

Please help, how to fix only menu upside the site?

Make your menu fix and background white.

The difficult is only that first part should go outside of screen while I’m scrolling down, and the navbar should be on the screen in the up line

But not fixed in the middle, while I’m scrolling down…

And when I go upside the side it should be on the right place, when it was