Hi nathalier,
Many Test Takers are unhappy with their initial practice scores, but you really shouldn't be. It's just a measure of your skills right now - and you'll be working over the next several months to learn the necessary content and Tactics to score higher. That having been said, raising a 380 to a 680+ will likely require at least another 3 months of consistent, guided study - and you'll have to make significant improvements to how you handle BOTH the Quant and Verbal sections. Thankfully, the GMAT is a consistent, predictable Exam, so you CAN train to score at a higher level.
Before I can offer you the specific advice that you’re looking for, it would help if you could provide a bit more information on your timeline and your goals:
1) What were the Quant and Verbal Scaled Scores for this practice CAT Test?
2) Did you finish each section? Did you have to rush through any questions just to finish (or leave any questions unanswered?)? If so, then how many in each section?
3) If you're already a full-time student, then how many hours do you think you can consistently study each week?
GMAT assassins aren't born, they're made,
Rich