In an integrated application/setup development environment, the original developer should modify the WiX source files in sync with the application development. As soon as a new module has been started, a new registry entry, service or other dependency has been coded, the appropriate setup modification should be made in parallel. Using this approach, no important information will ever be lost and, as a bonus, the setup program will be practically finished together with the application itself.
If you prefer a more traditional URL, you'll need to purchase one from the likes of GoDaddy or Namecheap. Domain name pricing can range from extremely cheap to extremely expensive, depending on whether or not domain squatters are looking to flip a valuable piece of online real estate. You'll want to get something short but evocative and catchy, and depending on what you do, you may find that many of your first choices are taken by either other legit domains, or by squatters who've scooped up the names as an investment. For more, please read How to Register a Domain Name.
A website is a collection of many types of content. Your website can contain a collection of content including blog posts, product descriptions, images that highlight your product, explainer videos that tell your story, and contact information. These different types of content have one thing in common. Each piece of content has seconds to capture the attention of your audience.