oh, I also have to mention codewars. That site was absolutely instrumental in giving me the confidence that maybe I could actually learn this shit. The first kata I did was as simple as "convert the boolean to a string," but that was exactly what I needed! I also like how it's less corporate than leetcode.
They offer courses supported by YouTube videos. They also offer certifications for subjects like JavaScript Algorithms and Data Structures, Backend Development and APIs, and Machine Learning with Python.