September 2 is rather soon...that's in 2 days?!
I think you'll need more time to prepare. You can check out the GMATPill one-month study plan
and see if that's something that fits your schedule.
If you are simply taking the test for fun, you can go ahead. But I would highly recommend preparing before hand, taking some of the GMATPrep practice tests so you know what range you're in, and then study and prep for the exam so you can score as high as you can and avoid time wasted retaking the exam.
... and more
What's Inside GMAT Pill?
Zeke Lee, GMAT Pill Study Method (Study Less. Score More.)
GMAT Pill Reviews | GMAT PILL Free Practice Test