The process of converting HTML static website to the WordPress dynamic theme is called WordPress theme development. It means you as a business owner can put your website on WordPress Content Management System and manage your website by your own.
If you already have website and want to convert it to WordPress theme, you need to know PHP and WordPress template tags. CSS sheet and all elements of your website such as menus, sidebars, header, footer, and main body should be converted. You need to use many PHP loops and hooks to make your theme a WP-Theme.
*If you do not have website, I can design your website and provide design documents. Then I would start coding your website and create template HTML pages for your website. Eventually I would start WP theme conversion and put everything on WordPress CMS engine.
*If you already have website, I would start converting all elements. First of all I make back up of every things and then I should distinguish all pieces and parts. Eventually it would be the time of conversion. Using template tags and converting everything.