Don't be afraid! I am in my first semester and I've been pumped about nursing school since before I even applied to the college to finish up my prereqs. I will not lie, nursing school is hard and is a whole different ballgame. Despite the challenges I love my program and I'm so excited to go to school and learn something new every day. It is a LOT of work, a LOT of reading, but it's alll there for a reason. Your program might be completely different than mine, of course, but the best advice I can give you is to be as prepared as you possibly can (do your reading, use outside resources), do the extra assignments even if they are only for your benefit and don't count for a grade, and don't worry so much about test grades. You want to pass, of course, but what a lot of people fail to realize is that the tests aren't a measure of your intelligence, they're testing your clinical reasoning. As you're reading, think of how you'd apply the information in a clinical setting. Try to "think like a nurse".. What really helps me is NCLEX-style questions. I was doing them way before I even started my ADN program. You get a lot of information from the rationales and even if you don't know the information yet it's GOING to come up sooner or later. Familiarizing yourself with those type questions will probably make test-taking a lot easier.
Most of all BE POSITIVE and LOVE NURSING! You can do this!