Great question! Yes, take your practice test right away (it's assigned on your syllabus to do "by class 2").
Then, use the below article to analyze your strengths and weaknesses:
http://www.manhattangmat.com/blog/index ... ice-tests/For your weakest quant areas, start going through the relevant chapters in your Foundations of Math book. Ditto for verbal (in your Foundations of Verbal book).
If you feel as though the foundations material is easy for you / you don't need to do it, then feel free to get a head-start on your first homework assignments. Let me know if you have any other questions!