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.
This tutorial is designed to help beginners get started on their own so WordPress and a pre made theme are a great way to dive in and build a website from scratch. You can of course design your own WordPress theme or pick up a premium theme such as Bridge, Divi or X-Theme from Themeforest which you can customise a fair bit. I have a post on fronted frameworks too if that helps you. learn to build a website