If you are a novice to Web Development, start with the basics of HTML, CSS, and JavaScript. These three languages are the most important skills for a web developer. After that, learn the basics of WordPress and then get to know UI (User Interface) and UX (User Experience). Even though learning SQL and PHP is optional but I recommend having knowledge of these languages. Also, having a basic knowledge of SEO is important for a web developer.
If you want to learn web development from top instructors, you can sign up for this Web Development Online Course by Intellipaat.
Also, you can check out this video for more information: