Every school is different regarding policies for living on campus. Some schools require it freshman year, some additional years and some don’t even guarantee you’ll get housing freshman year.
Some schools do have singles available to freshmen, but they aren’t guaranteed. If there is a reason you NEED a single (medical, mental health, gender identity, etc) you can usually work with the Office of Disabilities.
In terms of how the school sees it, I don’t think they really care in terms of seeing it as “selfish”. They only care if you follow the policy or not.
Housing information should be available on each school’s website.