Hi magdalenacoronel,
Many Test Takers are unhappy about their first practice CAT scores, so you're not alone. The GMAT is a Test that has some 'elements' to it that you probably are not comfortable with yet, so more study is required. Many Test Takers spend 3 months (or more) on their studies before they hit their 'peak' scores, so it's likely that you just have not put in enough time and effort yet.
1) When are you planning to apply to Business School?
2) Do you know which Schools you plan to apply to?
3) What is your goal score?
You mentioned that your GMAT is in a month, but that's probably not going to be enough time for you to raise your score up to a competitive level, so it's likely that you're going to have to push back your Test Date.
GMAT assassins aren't born, they're made,
Rich