Unfortunately, a lot of the more advanced lessons are locked behind a Pro subscription, but they do offer a free trial, and discounts for students.
Code Academy is a website that provides free lessons, resources, and challenges for those looking not only to learn coding for the first time, but also professionals looking to sharpen their coding skills. Code Academy is neat because they offer courses based on either a specific programming language, or a specific subject or career path. This is great for students who know what they're interested in, say Web Development, but maybe aren't sure about what exactly they need to study to become a professional web developer. Unfortunately, a lot of the more advanced lessons are locked behind a Pro subscription, but they do offer a free trial, and discounts for students.