I was in Army ROTC at Notre Dame decades ago, so my info is definitely dated. At the time I was on campus, most of the Army ROTC cadets were on scholarship. In general, I would say that if you are a competitive applicant for admission to ND, you will be a competitive applicant for an ROTC scholarship. (And as noted in post #2, the ROTC scholarship is applied for separately and awarded by the military, not by the school.)
Regarding life on campus, yes, live is pretty similar to non-ROTC peers. I took one military science class per semester, for which I wore a uniform to class. If I happened to have non-ROTC classes before or after my ROTC class, or if my schedule bumped that up against a meal, then I wore my uniform into non-ROTC classes and/or the dining hall. The class met maybe twice a week in a classroom, plus there was one afternoon “lab”. In addition to ROTC class, we had PT (physical training) two mornings a week at 6:30am. We were finished before most classmates were awake. Periodically, we would have weekend field exercises. And then there were also optional extra-curricular ROTC activities we could participate in.
Also, I’m guessing there’s info that can be found online. I looked up only ND’s Army ROTC, but here’s a link with some info:
To ask more specific questions, I would recommend reaching out to the Professor of Military Science (head of the “department”) of the particular ROTC programs that interest you.
Good luck!