On about halls in general, rather than specific unis...
People borrow each others cookware if they don't have their own, usually more obscure stuff like whisks and things. But generally as you've only just met each other, you'll ask first is it ok to borrow this.
Some people do shopping together... my two friends buy and cook together, as it's sometimes alot easier to cook portions for two than one and can work out alot cheaper, but you don't have to. But a trip to the shops together is always fun. Stuff like washing up liquid, kitchen roll etc is usually taken in turns (although not strictly, no rotas or anything) but you could just all use your own.
Stealing food is circumstantial. If I cook a meal and realise I've ran out of salt or milk or something, I'll ask can I borrow someones or once you get to know someone really well I'll just borrow someones if it's only a little I need, then tell them afterwards and they can borrow some back when I've bought it. But I wouldn't eat someones cheese or fruit or meal foods, unless they offered to share or give me some. Just go by what you would want done to yourself. Because you've only just met people will generally always ask first so you can set the 'boundaries' then as such.