You must have watched enough zombie movies by now to know that those not properly prepared are just walking food for ravenous undead hoards. Get your stuff together and map out your survival route with the aid of this handy dandy Map of the Dead. Plot your route via hospitals, food stores, bars, and even gun stores to get you the heck out of dodge.
OK, this is Britain, so the best you’ll probably manage as far as guns and ammo goes is a crossbow – then again a crossbow is silent and reusable, so perhaps it’s your best bet. Apparently there is a gun shop just round the corner from me according to the map though.