Codecademy provides a live coding environment to write code, display output, and receive live feedback. The free version has some features that can help you learn how to code. You can practice different languages: HTML, CSS, JavaScript, SQL, Python, among others.

W3Schools is a web developer site, with tutorials and references on web development languages such as HTML, CSS, JavaScript, PHP, SQL, Python, jQuery, Java, C++, C#, React, Node.js, XML, W3.CSS, and Bootstrap, covering most aspects of web programming.

From their website: "If you are new to programming, we recommend you start at the beginning and earn these certifications in order. To earn each certification, build its 5 required projects and get all their tests to pass. You can add these certifications to your résumé or LinkedIn. But more important than the certifications is the practice you get along the way. Practice is the key. Practice, practice, practice. And this curriculum will give you thousands of hours of hands-on programming practice.

And if you want to learn more math and computer science theory, we also have thousands of hours of video courses on freeCodeCamp's YouTube channel.