The path to becoming a Full Stack Developer is not necessarily about rushing but rather concentrating on the important aspects of development. Therefore, the first thing to do is to master HTML, CSS, and JavaScript.
Then choose a front-end framework (React, Vue, or Angular), and understand how to create responsive and user-friendly applications. In addition, select a single back-end technology (Node.js with Express or Python with Django).
Learn how APIs work and implement an example of connecting the front end to the back end. It is essential not to study too many technologies but to focus on understanding the basics.
Practice creating full-stack applications as soon as possible, even simple ones (a to-do list application, blog, or e-commerce). At least master version control tools (Git) and hosting services (GitHub).