Nursing

I am in my last year of high school and have been accepted for practical nursing (LPN). I’m not sure if any of you would know but I am unsure who to ask. I am interested in becoming a labour and delivery nurse or something similar when I am finished with school. But I was wondering if i am able to since I am only going to college, do I have to be a RN to specialize in a certain area. Btw I am in Ontario, Canada so if people have information about this please help me out. Thank you