Hi nachomontegu,
To start, studying for the GMAT now - far in advance of when you will actually "need" your Score - is a smart choice. Many GMATers spend 3 months (or more) of consistent study time before they hit their 'peak' scores though, so if you have been studying for just 1 month, then you should not expect to have mastered any of the question types just yet.
Before we can discuss how best to approach this next phase of your studies, we need to assess your current 'ability level.' As such, taking a CAT/mock this weekend is a good idea. Make sure to take it in a realistic fashion that matches-up with what you will face when you take the Official GMAT (take the FULL CAT - with the Essay and IR sections, at the same time of day as when you'll take the Official GMAT, if you will be at a Test Facility, then wear a face mask, etc.). Once you have that Score, you should post back here (or you can feel free to PM me directly) and we can discuss the results and how you might best proceed with your studies.
GMAT assassins aren't born, they're made,
Rich