Step 1: Navigate to Appearance from your admin dashboard then click Customize. Next, hit Header > General.
Step 2: Here you can choose the header type, background color, edit padding and margin, edit the Header Right text and background image.
Note: If you have imported the demo, you will not be able to see the changes you made because the page already had a fixed header style.
Step 3: After customizing, do not forget to click Publish button to save your changes.