CNA training classes are usually between six and eight weeks long. During training you learn to provide assistance with activities of daily living to clients which are elderly, sick, or disabled. A registered nurse program involves a lot more studying than a CNA course and a different exam. Associate degree nursing programs require at least two years of study and clinical practice, while bachelor degree programs require four years of study and hands-on practice. After graduation from an approved nursing program, you need to pass the NCLEX exam to become an RN or LPN.