Courses with gym-like approach to learning art?

I've been doing Drawabox since the start of my art journey, and drills and exercises that force you to iterate and practice a lot work wonders for me

But the thing is, I am almost through the course and, while I am planning to go over it again and practice drills from it, I need to move on with my skills

Are there other courses or books/platforms that have less lectures and more practice and gym-like repetitions one can follow? Because regular courses I found online focus a lot on theory, but not nearly enough on practice and what, how much and how

As well as courses frequently require to rely on teachers' feedback, and I am autistic and find interactions very tiring, but can learn on my own if I have a point of reference on what level should I get to to move on onto the next task

Any recommendations?

Thanks in advance!