I’m sure most 13 year olds plead with their parents to take them certain places or buy them certain things (e.g. specific food and clothes, etc.), and while I’ve never been to boarding school, I imagine you have to figure out how to get things for yourself.
The point is taken re: not being “sink or swim” (you won’t be left on a ditch on the side of the road), but surely it’s obvious that more independence is needed living without a primary caregiver in the same home.
The adults should be ensuring you don't grievously injure or harm yourself, and that you're returned in same/better condition.
You can always ring up your parents and ask for stuff, it's not like you are adopted by the school and lose all contact with your parents, nor are you earning a wage at 13 going to boarding school.
Lots of kids going to public school and/or with rough home lives learn "sink or swim" just as well or better than someone going to boarding school. I just found it odd to say you're learning to "sink or swim" when you have so many safety nets there to catch you if you did sink/fall.