You can configure your header layout by going to Customize > Header > Main Header > Layout:
Select the layout you want to use, then scroll down a bit to find the options under the Elements heading. Using these options, you can add additional elements to your header, depending on the header layout you’ve chosen previously. The locations in which you can add additional elements are highlighted below.
You can use these sortable fields to select the elements you want to display:
Based on your element choices, new options will show up automatically in the Customizer. You can use these options to configure your selected elements.