Budgets will mean nothing, especially during freshers.
The way I managed on my loan was to eat extremely cheaply and RARELY buy takeaways, I bought maybe three McDonalds and pizza then subway when my bro visited in my first 2 years.
Butchers and greengrocers are your friend as are LIDL/ALDI.
Always have something delicious and available to reheat at home/halls after a night out, this will save so much money.
It can be tough though, when I was at uni 2006> I could get a full week of shopping for about £11-14. It's surely much more now.