Yes. As with much in life, it's good to take a step bck for a moment and ask yourself "how would we have done this when I was that age?"
How did I find out about the post? I can't fully remember but we had pigeon holes in halls that post ended up in and when I lived in a shared house it's just the normal post. My mum would send stuff to the Halls address (by "stuff" I mean a pillow case I forgot, letters, silly postcards), I don't know why it would be much more complicated than just putting the address on the thing you're sending.
Supermarket deliveries are something I've only ever used on a hen do, I go in person to the supermarket like it's 1994 and my 18 year old student son also physically walks around Lidl or Aldi. In the early 2000s I would walk to the nearest Somerfield or mini Sainsburys as I didn't have a car and I'd only need and get what I carry.
The student is the one who's in the place that has all the support and the answers. If they don't know where the nearest post office is, it's good practice for them to learn how to find out about that kind of thing. It's good for them to use the Halls support staff to find things out or to be signposted to information or help or advice about anything.
I believe we should let our young people bumble along and do more for themselves. My 18 year old is shy and anxious so he didn't even want to go to the freshers fayre. Rather than look up all the info he needs for him I made sure he went along but with two things in mind that he needed to find out (how to sign up for the gym, how to pay, what's the cost) and joining the specific sports club he wants to play in (when's training, how does he know fixtures). He was buzzing later that afternoon "they had free pizza!" with his new Dominoes vouchers, the contact info for the sports club (who'd spotted him and approached him & were really welcoming) and with enough info about the gym prices for him to make some decisions.
In the same way, he's had to book in his own driving lessons, phone the meningitis vaccination people to book his slot, all that kind of thing. I could do it for him but he has to flex those independence muscles and have a bit of control over his own diary, calendar, transport, responsibilities, health etc.