priyanshu2808I assuming these are results from the OG diagnostic test. Those are great results. Also, did you take the GMATPrep cold? If you did then 600 is a very good baseline, considering that you are just starting. I am just saying from experience.
You are clearly strong on the quant, and should mostly focus on the verbal. However, I would recommend you to study them concurrently, even if you end up emphasizing verbal. The reason has to do with keeping your brain fresh on both topics. I have seen students score drop on the verbal when they exclusively focus on quant, and vice versa.
Other than that I would say don't try to save official GMAT questions for the end. Try to spread the official GMAT questions throughout the entire GMAT preparation. There is plenty and you don't have to worry about exhausting them. For example, on the quant you have 450 questions in OG 2015, another 300 in Quant Review, 200 in Question Pack 1, and once you do the free GMATPrep practice tests you have around 700 quant questions in the database(Link here:
all-gmatprep-questions-quant-verbal-187679.html). The main reason for recommending the official GMAT questions is to get very used to the style, structure, and pattern of the GMAT, which takes some time to internalize, and the sooner you start with official questions, the quicker you will be ready for the official exam.
Cheers,
Dabral