I just signed up for a great beginner drawing course with https://store.arttutor.com/dl-4654371 
Even though I already draw fairly well I feel I always like to go back to the beginning and preferable with a different artist. Each instructor has their own way of teaching and combining several teaching methods one will find what resonated with you. 

Even before attempting to draw digital one has to master the pen and pencil. 
Stay tuned.😳🤓🌝