Hi Kc2.
The main thing you can do to speed up in answering GMAT questions is prepare effectively since skill in answering questions is what will enable to answer them quickly.
So, you don't need to retake that practice test. Your move is to proceed with your preparation and count on naturally getting faster as you learn.
Also, at this point in your preparation, you should be less concerned with speed than with precision and accuracy. Your first order of business is to learn to get questions correct consistently.
That said, if you'd still like to get some insights into how to speed up on the GMAT, you can read the following posts to learn how to get faster at GMAT Quant and GMAT Verbal.
How to Get Faster at GMAT Quant QuestionsHow to Get Faster at GMAT Verbal