I think it better to start doing the learning mode first (without time, to understand the concept). Try to practice 20 20 by processing groups. At least 100 for each group (100 initialing, (100, planning ), etc. Repeat the exam second time but to correct your mistakes on the first try( select the option "only questions that I answered incorrectly"). Continue trying all the quizzes in all processing groups. If you not understanding something, go to the book see what it has. after one or two weeks at least you should get good knowledge. Now, go practice the time exam, at least 6 full exams, and see how you will do
on them.