The first portion of this tutorial described how to take components of WordPress and integrate them into your existing site. You may wish to stop right now, but perhaps you would like to create a WordPress theme that would eventually replace web pages on your site.
You will need to create a custom theme. A theme is a set of files used to tell WordPress how to display the site and Using_Themes is fundamental to WordPress. You may create your own theme from scratch, but you should consider to create the Child Theme of existing theme as the first step. The child theme can enhance or customize the limited portions of existing theme. Refer Child Theme for more detail.
A little known, but very helpful HTML element,