There are a number of ways to get started. You can use an online website-building service like Wix, Weebly or Squarespace. Or you can go with something a little more robust like WordPress, which offers two options: a hosted solution available at WordPress.com or a custom installation at WordPress.org. (See how WordPress.com and WordPress.org are different here.)
There are other options similar to WordPress, like Drupal and Joomla, which plenty of professionals swear by. Which one you choose is mostly a matter of personal preference, and what you're trying to accomplish with your website.
Once you've chosen a hosting company that you're happy with, you're ready to build the website! See our guide to the perfect website layout for help with the website design and build.
So there you have it! If you don't already have a website, you need to get one ASAP. If you do, make sure it's up-to-date, with a fresh, responsive design – otherwise, you might as well not have one at all.