Well my first advice would be to go to mba.com and download the GMATprep software (it is free). Familiarize yourself with the question types with their practice questions, and then take a practice test. Put aside 3-4 hours, and take an actual test. Then once you know where you are starting score is, then you will know how far you need to go. A 600 in two weeks is different for some people. For instance, without cracking a book I scored a 570, so within 2 weeks I could have scored a 600. But for someone that scores a 400 without cracking a book, a 600 in two weeks will be nearly impossible.
Once you have your score, then review all right and wrong questions and figure out where your weakest sections are. You will need to improve these immediately. 2 weeks preparation is not enough. 3 months of intensive study is usually recommended, so you are behind the ball.
Good luck