I've been adding videos about JavaScript to my youtube channel and you can take a look at it here: https://www.youtube.com/channel/UCqdNQHOLz3PmB4cDvQkdQ1w/videos
They are not professionally produced. I just turn on youtube and start typing generally. You may have heard of "rubber duck decoding" and this is basically how I make these videos. They are either me talking through some code I've just worked on or some are videos I've made where I'm trying to help a friend out with some coding issue.