First determine what you enjoy about website design, is it the design aspect or the coding aspect?

If you enjoy designing websites (and are good at it) try to get photoshop or Sketch. Sketch is the best in my opinion but it is only available for Apple computers. Once you have an understanding how to use the tool, design your website. Next you have two options, either have clients and design a custom website for their needs and build it in a website builder. (I recommend Webflow for this because they produce clean code, and you are able to integrate many applications into your website as needed), or create a template, price it an affordable $20-$50 and put it up on a market place. Then wait for people to purchase it over time.

If you like the coding aspect and have knowledge of code then see if you could find freelance UI/UX designers that are in need of a coder and have them hire you to develop their websites. Or simply find clients yourself, purchase a template for them, edit it to their needs, and your done.

Click this link to start; https://www.fiverr.com/share/77D6gx