One of the most important bits of advice is, on your first big shop it to stock up on the basics!
If you’re lucky enough to convince your rents to do your first big shop at uni (and even if you aren't), DON’T just put alcohol in the trolley (although essential), also make sure you do some bulk buying of store cupboard essentials, that way they’ll be in the back of your cupboard for the rest of term and it works out much cheaper in the long run!