I'm not sure where to begin with answering this. From your other thread, I assume you're a complete beginner at web design.
You can design a page in Photoshop, if that's how you prefer to work, but you need to use HTML and CSS to implement that page on a web site. Are you able to do that, or is somebody else going to be doing that part? I'm assuming from your description that you want this page to be effectively the home page of the site. I don't know enough about WordPress to know how you would go about replacing the home page with a custom page that is different to the rest of the site, but I don't imagine it's an easy task for a beginner. I think you'd also need to know PHP in order to customise the page like that.
With what? With designing your page? You need to work out exactly what content will be on the page, and then consider the best and most logical arrangement of that content. Start from there, and once you have that sorted, then you can start to think about design, etc.