While CNA training is helpful, it now requires a lot of schooling to get the certification and then you're in a fairly low paid job. For current CNAs it's smart to take the certification they have and look for a bridge program to nursing school.
But if you want to be a nurse, then apply to nursing school. Find out what the prerequisite classes are for both community college (ADN) and university (BSN) programs and start taking the classes at a community college, where it's cheaper. Contact advisors at both types of schools and get advice on how to be the best applicant possible. Then apply and see where you're accepted.
Getting a BSN right off is ideal, but it's still okay to go the ADN route if that's where you're accepted. Like others have said, you may not be able to get a hospital job with an ADN, but you can still find jobs in long term care. Some employers will then help you pay to bridge from your ADN to BSN.
You do need decent math skills to become a nurse, especially algebra, which will be used in Chemistry and also Statistics. But don't fear these classes. Take them and do your best. Ask the teacher for help and get books like "Algebra for Dummies" to help you get the skills. I believe ANYONE can pass classes like Algebra and Chemistry if they keep up with the work, do every assignment, and struggle through to master the tough concepts. Not only will this help you towards nursing school, but you'll feel like a rock star for overcoming a difficult challenge. Good luck.