First step to set up a website is that you need a good web hosting provider who supports WHMCS.
Second step is to register a domain name for your website. You can check out for many web hosting providers that offer domain registration services.
Most web hosting providers offer seamless installation of WHMCS through tools likes Softaculous or fantastico.
Once you have installed your WHMCS, you may need to configure it.
WHMCS provides default templates, but you may want to customize the design to match your branding.