2 weeks… grab a GMAT test prep book, and just learn the format. its really not that hard. but make sure that you don’t rush, and ensure that your first 7 questions for a given set are 100% correct… you’ll end up having a higher score in the end due to their crazy point system.
the math section is basic stuff that you learned in 7th grade… really. its that easy, just remember your basic “math rules”
plus, depending on where you are applying, you may not need an amazingly high score.