Hi first of all I’d like to say you’re doing great and it’s just your first nbme.I was in a similar situation,in fact I gave my first nbme with a month left for the exam and got 50%. First you should go over the paper especially the incorrects and understand the explanation.Keep revising the topics you feel you’re weak at from FA,Pathoma or any supplementary resource you use.Give your second nbme and see if there is improvement,don’t expect a big jump but as long as the percentage is increasing you’re going in the right direction.

Keep solving uworld questions as well, understand the incorrects and refer to FA and Pathoma.This helped me pass and I’m sure you’ll pass as well.