You will learn a lot from taking the practice test, but the real learning begins when you review your answers. Surprisingly, you can learn just as much from the questions you answer correctly as those you answered incorrectly. Once you have completed your practice test, give yourself a break, and return to your test. (Score yourself first, if you must.)
Once you have cleared your head, sit down with your test, and go through each test question and its rationale. If you answered a question correctly, briefly re-exam each incorrect option for that question and recall why that option is not correct. This step is crucial in reviewing your practice test because even though you got the answer correct, you will validate your understanding of the subject in question.