Hi
Lepe96 ,
Welcome to GMATClub

As you mentioned this is your first CAT, I think this is a great score. You are already at a great start.
Yes,
MGMAT Quant is a bit harder than the real GMAT but I believe it's better to practice such questions as once you get comfortable with such questions, you will find actual Quant very easy.

Rushing through the exam is the BIGGEST cause of getting lower than the desired score.
I believe you MUST work on your time management and work on the content also.Give 5-6 mocks and see whether you are maintaining the consistency in your scores.
If yes, practice a little more and you are good to go. Try to give official Mocks also as they are obviously the TRUE indicator of where you stand.
All the best.