Please how can I complete my electronics knowledge
(although the Art of Electronics is incredibly dense material)
You have a point. Although it includes basic material, it doesn't teach it at a basic level. For an electronics person, maybe the most complete book. For a student without a teacher, it can be a level too high.
I think if you can pass the Linear Systems (resistors, inductors, capacitors in DC and AC context, Network/circuit analysis) course and exam on Coursera, you're at a point where you can step up to self-learning.
if you don't have the grasp of the linear part, and can't resolve a circuit, you'll be able to copy other designs, but designing will always be tough - because that base is needed.
edit: ahumm 
It's a "Statement of Accomplishment" because I didn't pay for the controlled path. But I took the same course and exam.
