If you are concerned about the math, buy a book and start learning how to calculate dosages. It isn't hard, but it does stump alot of nursing students. I know we lost at least 1/6 of our class to math our first semester (they weren't able to progress to the next semester because you had to make at least an 85 on the dosage calculations final.)
I bought the book by Springhouse "Dosage Calculations made incredibly easy", and I used it in addition to our textbook, and I passed the class with flying colors (I'm not a math person, either).
Or, if you can buy your textbook early, and just start working through it, it will really help you. The first semester of nursing school
is a big adjustment--it's just so different from the other classes you will have taken--you don't want to have the added stress of worrying about whether you'll pass math or not.