For exercises, you should spend more time thinking independently instead of doing the exercises, but you should also control the time schedule and don't memorize a chapter for a few days. If it is too inefficient to do the problem independently in a chapter, you can choose to skip the rest of the exercises in this chapter first, so as not to affect the progress of the book.
There is no fixed order for drawing small blueprints. In principle, you can choose those who have a corresponding knowledge base or feel "comfortable".