Hi ryo1999,
You're ultimately asking Admissions questions, so you would likely find it beneficial to speak with an Admissions Expert about your overall profile and plans. Those Experts should be able to answer your Admissions questions and help define the specific areas of your profile that could use some improvement.
There's a Forum full of those Experts here:
https://gmatclub.com/forum/ask-admissio ... tants-124/From your first post, I have to assume that you have not done any studying for the GMAT yet.
If you're just beginning your GMAT studies, then it would be a good idea to take a FULL-LENGTH practice CAT Test; you can access 2 for free from
www.mba.com (and they come with some additional practice materials). If you want to do a bit of practice first, so that you can familiarize yourself with the general content and question types first, then that's fine - but you shouldn't wait too long to take that initial CAT. A FULL CAT takes about 3.5 hours to complete, so make sure that you've set aside enough time to take it in one sitting. Once you have those scores, you should report back here and we can come up with a study plan.
In addition, I'd like to know a bit more about your timeline and goals:
1) How long have you been studying for the GRE?
2) When are you planning to apply to School?
3) When would you want to take the GMAT (or potentially retake the GRE)?
GMAT assassins aren't born, they're made,
Rich