Hi aettin,
It sounds like you're just beginning your studies - is that the case? If so, then it would be a good idea to take a FULL-LENGTH practice CAT Test; you can download 2 for free from
www.mba.com (and they come with some additional practice materials). If you want to do a little studying first, so that you can familiarize yourself with the basic content and question types, then that's okay - but you shouldn't wait too long to take that initial CAT. That score will give us a good sense of your natural strengths and weaknesses and will help provide a basis for comparison as you continue to study. A FULL CAT takes about 4 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.
Many GMATers have busy lives in addition to studying, so you're not alone. One of the tricky aspects of integrating a fixed classroom schedule into your busy life is that you might not be able to set aside the necessary time to take those classes when they run. Thankfully, there are lots of options when it comes to studying (including Self-Study Courses that give you all of the necessary lessons/materials/etc. and allow you to study at your pace and when your schedule allows).
I'd like to know a bit more about your timeline and goals:
1) What is your goal score?
2) When you say that you want to take the GMAT around June, does that mean 'early June' or "late June?"
3) When are you planning to apply to Business School?
GMAT assassins aren't born, they're made,
Rich