Is it possible to set the header width? I only found the option to adjust the height, with no setting for width. I want to customize a specific width and keep it centered.
The header width depends on the General Layout of the site. If you want to make the boxed header, you need to set the Boxed layout in the Theme Settings > General layout, and the header would be boxed.
Regarding to your highlighted screenshots, Navigate to WoodMart > Header Builder > Edit Current header and click on the Settings button and enable the “Make it overlap” option and “Make it boxed” https://postimg.cc/xXnQMK6H