How to set the default Header Style

These settings can be overridden by settings from Page Options Box in the separator page
These header settings are for the whole website. If you want to use a different header style for different posts or pages, then please go to the specific section.
Step 1: Navigate to Appearance from your admin dashboard then click Customize
Step 2: Find Header > General
Step 3: Choose the Header Style you want in Global Header Style section. There are 8 different header styles for you to select from.
Now the chosen header style is set to be the default header of all pages. However, you can still set a different header style for particular pages, blogs, products or portfolios by setting a style in each section.
Note: If you have imported the demo, the header of the landing page is fixed in page settings (we will discuss this later on in the Page section). Therefore, if you want to try setting up the default header style, you would have to create a new page.
You can change header style, there are 9 header styles & you can enable overlay, choose dark/light skin
You are also can add a button on the header
Step 4: Click on Publish button to finish.

How to customize the Header Style

Step 1: Navigate to Theme Options from your admin dashboard. Next, hit Header. You can see a list of available header styles.
Step 2: Click on the header style you want to customize.
Step 3: In each Header Style, you can customize Header Components, Header Navigation...
Note: Maybe you will not be able to see the changes you made because the page already had a priority settings in Page Options, then you can go to the page to check again.
Step 4: After customizing, do not forget to click Save Changes button to save your changes.

How to use the Sticky Header

A sticky header has its position fixed at the top of your webpage even when users scroll down to navigate the page. This allows users to quickly access the menu from any section of the page.
All you need is to hit Header Sticky in Header section.
Now you can enable or disable the Sticky Header.
In addition, you can also customize its Behaviour, Background, Header Icons, Button... of the Sticky Header.