You'll get to experience different areas while doing clinicals in nursing school, but if you want to become a peds nurse after you graduate, I would suggest getting a job as a student nurse extern on a peds unit part-time during school, or the holidays, and full-time in the summer. A lot of hospitals have these opportunities, and this is a great way to get your foot in the door once you do graduate and to also make sure peds nursing or PICU nursing is really what you want to do once you're an RN. Hope this helps!