We did this last year and bought more than was actually needed.
Not needed:
Kettle
Toaster
Microwave
(Also airfryer, though a flatmate does use the one we bought for DS)
Appreciated and used:
Ikea kitchen starter kit (Wilko do a similar one)
Shopping trolley bag on wheels (used lots)
Towels
Bathmat
Tea towels
Cleaning products & washing powder (not pods)
A rug, plants, personal choice of bedding + a spare set.
Air bed for friends to sleep over (single size)
Essential first aid kit and flu meds (freshers flu is real)
A Lidle Gift card for emergency food shops
Toiletries
Iron
Hairdryer
Kitchen cupboard basics of herbs, seasoning and sauces, pasta, rice and Noodles, tea, coffee etc.
A pack of those dehumidifiers turned out to be essential in this particular accommodation.
What we wish we knew beforehand was the expense of Freshers week events and cost of socialising in those first few days, before the funding comes in, there's lots of peer pressure to go to everything, but now it seems to have settled down and most friends of his have found some paid work by their January return. We paid for a year's gym membership as DS likes the one near our home, but he hasn't used the campus gym at all so far.
A cinema gift card is a useful Christmas gift.
A printer has also been useful and appreciated, both for study and for printing photos to have on his walls.
Prepare now by teaching real budgeting and costs of things.
The full student loan still didn't cover the costs of accommodation, there's no guarantee that you'll be given the cheapest, so get organised to request and reserve as soon as booking goes live. We have to top up funds often and its not easy, but DS shows his bank account and he's definitely not spending wildly. His student bank account comes with a very useful overdraft facility, which does help for short-term urgent needs.