I would take a full practice test and after you're finished, look at the types of questions that you got wrong. If you haven't taken a full practice test yet I would recommend it so you have a baseline score for yourself. A lot of the time you'll notice certain types of questions trip you up more than others. Its best I think to drill those types of questions that you have the most difficulty with as well as supplementing your drilling of those questions with the specific lessons on those question types. I don't see a lot of value in going through all the lessons first without drilling or figuring out what your particular strengths and weaknesses are. That might be a little bit aimless. Practice tests can be used to identify your specific weaknesses and then in the lessons you can learn skills that can help you overcome those weaknesses. Drills then, can be used to practice those skills and hopefully not get those question types wrong as frequently on an actual test.