To set the header to the Centered layout navigate to Appearance > Customize > Header and select “Centered” from the Layout dropdown.
When the header is using the Centered layout the logo / site title and navigation are centered.
Top Bar
An additional feature of Centered mode is a Top Bar which has a Top Bar Left and Top Bar Right location that can be set to display either informational text, social media links, WooCommerce shopping cart and account login links or a custom menu. Alternatively these locations can just be set to display nothing.