Many hosting services, including SiteGround, will provide a free domain name when you sign up for their service. It will also simplify your life to have your hosting service manage your domain since it keeps everything in one place.
If you already have a domain name, you can skip this step. If you need a domain name, check to see if you can use the name of your farm. Most hosting services, including SiteGround, provide a way to search domain names to determine if the one you want is available.
If your farm name is not available with a .com extension, you might try other extensions–or add small variations to your farm name to create a unique domain name: For example, instead of sunshinefarm.com, you might use thesunshinefarm.com or sunshinefarmtx.com.