Since you haven't begun college yet, you could start applying for NCP the spring of your freshman year and there would be 10 spots available. If you don't get accepted, you can apply again the spring of your sophomore year and there will be 65 spots available. I began applying spring of sophomore year and it's my first time applying. If you were to apply freshman year you have to already have acceptance into your BSN program.
Normally about 125-150 apply, but this year had a very low number of applicants - no one knows the exact number but it is less than 100.
And it is true, you don't have to do anything except for do well in school until you graduate
The minimum GPA requirement is 3.0, but from what I've heard a low GPA can hurt your chances of getting in. A 3.5 or above is considered competitive for this program.
If you have any more questions feel free to ask!