Question for L & D nurses

I study to be a L&D nurse, but I have some worries. I come from a low income family, ik scared that medical school will be too expensive. How many years of school is it and typically how many hours do you work? I have a child, (I'm 18. Hes 3 years old), I want to have time for him, but I also really do want to become a nurse or even a doctor, especially in that field (births). I just want to make sure I can complete my dream career without being completely broke and have time for my baby. (Please no hate on my age when I had my baby, its a long and sad story).