I'd recommend starting with the channel Surface Studios the guy is absolutely amazing, and back in 2010 when I was dabbling in AE he was the go to guy. He has playlists already in order of advancement so you can start at the level you feel you are at and work up from there.
This isn’t a channel, but I do recommend watching Linda.com videos. They’ve been super helpful for me and cover more than just After Effects (all the Adobe suite, Maya/Blender, Autocad, etc.)
Otherwise I’d just recommend typing in the YouTube search something along the lines of “After Effects video editing” and see what titles peak your interest.