Read. Write. Execute. RWX. I'm going to piss some people off. Here goes: you are wasting your time if you watch videos. At all. A video moves at the pace it plays. It is linear. You can't jump around easily. Reading? You can jump wherever you need immediately. You can have multiple sources at once. If you use a book, yes a physical book, you learn where things are and jump right to them. Read
Write down a paraphrased version of what you read. Do not copy. Include references so you can return to source if needed. Note taking is a skill. Your notes should be organized in a way you can skim what you wrote as easily as the sources themselves.
Execute. You don't learn anything unless you do it. I've had too many students who watch Khan Academy, and think they understand it when they haven't done it. They don't score well on exams. Not my fault. I told them they have to do it to understand it.
RWX. I await the flame war I just started with the video people.