Are you asking about a nursing assistant in a newborn nursery, nicu, or on a postpartum unit? You have to get your CNA ( Certified Nursing Asst) or PCT ( Patient Care Tech) that is usually 6 weeks to 3 mths program. It's hard to get into those departments without knowing someone or having experience already.
You will need about 2 to 3 years to complete your course. There may be another 6 months training by the employer as well. You can find out more from someone who has already completed the course or from a nursing school.