A month is actually a really long time in the context of exam prep if you use it wisely! I would start by taking a practice test so that you’re able to identify your areas of weakness, then work as many practice problems as possible to shore those up.
Finally then I would focus on your exam strategies … focusing on time management and learning to double check your answers by plugging in values can go a long way toward boosting your score.
I hope that helps get you moving in the right direction! Feel free to reach out if you have any more questions beyond that :)