Anyone can buy a domain name. To do so, you visit a domain name registrar, such as GoDaddy or Namecheap, key in the domain you want to buy, and pay a fee. You can't buy just any domain, of course—only one that isn't already registered by another person or business and that bears a valid domain suffix. In general, you'll want to buy something that is catchy and short so that it's both easy for people to remember, and easy for them to type in—like "PCMag," for example. That good search engine optimization (SEO) and it's also common sense. You might also want to do some research on key terms for your business. If you can get a good one into your site's name, that's all the better, from an SEO perspective.
Keep in mind, however, that free domain names are usually free only for one or two years, after which the registrar will bill you for the annual or biennial fee. In other words, the provider of the free domain name pays only for the first billing from the registrar. Also take note of whether or not the provider charges a fee for setting up a domain name. Most services offer to transfer an existing domain name to their servers at no cost, but sometimes you'll find a setup fee over and above the registrar's fee.
A great domain name is a concise, easy to type, and memorable URL that reflects your brand or your website’s subject matter. Avoid using hyphens, strings of numbers, or unnecessary words to make it easy for your visitors to remember and find your website. Remember: A great domain name is one that your visitors can type correctly on their first try.