Hi,
As Pavel said. In Joomla, all components works inside component area that is defined by template layout.
Yes, it's possible to build whole website using SPPB (but not recommended for beginners), but Joomla template has to be installed and enabled anyway.
The link that you shared doesn't look like Joomla CMS code, but I can guess that you want to build similar website using Joomla.
What "header" means for you? Logo and menu section? If yes, it has to be configured by Joomla template. You can start with raw, free: Helix Ultimate 2.0.x template.
Maybe start from youtube tutorials or take few basic lessons of Joomla from teacher (your country/city). Then it will be easier to start your task, if you are Joomla beginner.