When you create a new page, you will have options to change elements of Header :
Show Breadcrumb: Tick this box so that the breadcrumb can be shown on the page
Header setting: there is a drop-down list containing Header types to select
Menu Logo: Upload a Logo image
Navbar Position: There are 4 options that are Use Navbar Position in customizer, Static Top, Fix When Scroll To Top and Fixed Top.
Static Top, in this case, the NavBar does not move. It means that when you scroll down on the page and let the mouse pass the NavBar, you will not see the NavBar displayed on top. However, Fixed Top will allow you to see the NavBar when you scroll down the mouse. Meanwhile, Fix When Scroll To Top will allow you to see the NavBar when you scroll the mouse to the top.
♣ Note: In spite of what you set up in Customizer, all options in Page settings will always be prioritized.