There's so many benefit for creating your own site. For one, nobody owns your identity but you. With social media networks, free sites and blogs, you can be giving lots of traffic to a company that doesn't really care about you or know you personally. You have to take control of your identity online. You can still use social media and free blogs, but you should also have your own domain where people can go to check out everything you love. Registering a domain is the first step to getting this done. There's actually an awesome service with the cheapest domain name registration at Register.com. You can register any domain there for much cheaper than other places and even get private registration for a bargain price too. They also have bulk domain registration just in case you get a burst of creativity.
The main thing you want to consider when creating a domain is what people will think of your site. What will be your theme? How will you write content or post images? When you can think of a few keywords to describe what you're going to do with your site, you can come up with a creative domain name to register. You should probably a .COM but .NET and .ORG are also pretty popular and common in today's internet world. There will be a lot of new extensions released in the fall, so you can also watch for your favorite domain names to become available.