College course selection (Nursing) (CUNY)

I an still not 100% sure what I want to major in in college.
But I know I am interested in the science and health care field and nursing.

If I pick the nursing day course at a 4 year college can I change once I have all my prerequisites or do I have to do nursing as I’ve already picked it?

What about at a 2 year college? If I pick a community college and decide I dont want to do nursing anymore?

What’s the difference between picking the nursing course at a 4 year and 2 year college?

I know one is 4 years abd the other is 2.
I meant in terms of changes