Wordpress Landing Page | Duplicate from existing site

https://climatecarehsv.com/ Do not contact website owner/email or phone!! ONLY messge through here... as they are a client of mine,... They want to setup a duplicate homepage but to display a different # everywhere it is displayed or able to click.. including the header and footer... we want NO link to other pages as well on their real site... just a landing page with this new #.... the homepage look can be slightly modified if needed.... they want to use to to test a Google Adwords campaign... The rest of the site needs to stay as is...