Heads up on nursing?

Hello! I want to major in nursing and planning to become a pediatric NP in the future. What are some things I should know about nursing school? I don't have any extracurriculars that are healthcare-related since I just recently thought about nursing earlier in my junior year. I am slightly worried about that since most people tell students to do clubs, such as HOSA, that are related to their field. I couldn't join HOSA because of the competition fees, and that was out of reach for me. What can I do instead?

I don't know if this is true but I heard that it is possible to get accepted into a college but not their nursing program. But my question is, what would you do then?