Urban red foxes have been known to be a tad vicious or territorial and attack people... but it is not a common occurrence by any means, usually it's due to the fox having gotten itself into a cornered situation, they then act as any wild animal will and potentially strike. There is always the odd news story of a fox getting into a house, and attacking people... but it's uncommon, and for the majority of interactions, the fox only strikes as it cannot escape. The majority of them are simply made up by people who have had vague experiences... Not all pet dogs attack, but once bitten twice shy. Rabid foxes are also, like urban foxes, less wary of humans than their rural counterparts. Also an injured fox may attempt to bite you if you get too close, but this is common of any wild animal that has an injury.
That said, I've never had a bad experience with either an urban or rural red fox. Usually they just run away from you. I've seen some beautiful red foxes in my town, and out in the woods, they look at you, they may watch a while, but they don't come close, or let you get close.
Red foxes are not massive pack animals, but they will hunt with their cubs, to teach them until they move on on their own. They for the most part hunt small rodents, nothing bigger than a rabbit. Foxes are known to scavenge in bins, eat nuts and berries... they're opportunistic.
You will more likely see a fox at dusk, or at night, but they do not attack people so there is no worry about exploring an area either at day or night. That said you should always be respectful of whenever you are exploring, and be aware that your torchlight could easily disturb, or spook, a number of nocturnal animals.
Just a note when we have our dog around we actually have noticed the red foxes will linger longer... we recently had a fox run right into a field maybe 5 meters from us, stop dead and stare at the dog, then run off after a few seconds. Taking a dog exploring with you at night in a foxes habitat is something I would say you need to be aware of - but again the fox will likely just run.