Good questions. I would say that it honestly depends what you want to do and where you went. More doors will be opened for you if you went to an Ivy League school as there are a couple firms that only recruit their employees from those select schools. Getting into a graduate school also may be a bit easier if you went to Harvard as the name definitely carries some weight. Withstanding the few jobs that only recruit from Ivy League schools and having a leg up when applying to graduate school, I would say that going to a non-Ivy League doesn't necessarily put you at a disadvantage after your first job. Having a well known school never hurts and can only help, but people care less and less where you went to school compared to your capabilities and work history. I work for a Big 4 firm (PwC, Deloitte, KPMG, and EY) and my coworkers come from all schools and all walks of life. I work with a few ex-Marines, a former college lacrosse player, an attorney, a Cambridge grad, former government employees etc. By this, I am trying to say that having an Ivy background isn't the end all be all "golden ticket". Success is very much possible without having graduated from an Ivy League school.
If you have the chance to go to one of those schools, definitely go (if it's the right fit) as it can only help you in your future, but don't feel as if you are disadvantaged if you don't end up going to an Ivy school.
I hope this helps and I wish you the best of luck!!