I actually signed up for a course from Anthony of
Seed To Stage!
Amazing!
I took the mixing course and he has a songwriting course and a sound design course, as well. I am learning more in a day than I did in a month. He is also a successful musician.
The content of the mixing course is do deep I have been watching each video, applying the techniques and then going back and watching the videos again because after experimenting you really get a lot more out of the lessons the second time through.
I give his course an 11/10. It's beyond excellent. Now, the free content on his channel is second to none if you want to see what he is all about.
Good luck in your music and thanks!