please help me with deciding my career field as a nurse

hi there, this is my first time here. I recently started to think about becoming a nurse. Well i thought about becoming a dental hygienist. but nursing seems to have more career oppturnities. I am not in school right now and when i go back to school in spring,(i left 2years ago and i have one yr left at university) i want to change my major into nursing. I love helping ppl but i dont know if i can do it. I feel like im not capable enought to do anything... but i love challenging and am a very very word worker.
I just need some advise from ppl who are taking a path becoming a nurse or who are nurses. What should i expect before i get into a program, and after i get into a program. How hard is going to be? What am i be really doing as a nusrse? I may soundvery stupid. but i really need help!!!

thanks