freeCodeCamp.org on YouTube · Open on YouTube
Core skills: building for the web · Advanced beginner · Lesson 17 of 98 · 1 h 59 min video, then about 5 hours of practice
The DOM and events without a framework
After this you can select elements, respond to user events and update the page with plain JavaScript.
Why it matters
Frameworks like React exist to manage the DOM for you, and you will understand what they are doing only if you have done it by hand once. Select elements, listen for events, change content and classes, and handle a form submission. Build one small interactive thing (a to-do list, a calculator) with no framework at all. Trap: spending weeks here. You need the model, not mastery; React replaces most of this in practice.
How to use this resource
A current full course on the DOM. Build its exercises, then one small project of your own without it.