Although you did not know the city at all, you know that to the south there is a Division that separates the city from the rest of the country. Those creatures had attacked from the north so other attackers were likely coming from that direction. So your only viable options for leaving the city were to go west or east.
In the end, you choose to head west. It was the easiest option because you knew - vaguely - the way from the police station to the outskirts thanks to the 'tour' so kindly provided by the cops when they brought you from the outskirts to the police station.
You could use the ruins of collapsed buildings to hide from the advance of the invaders. Hopefully, you would find an abandoned vehicle that was in good shape and you would come out of this shithole.
Taking one last look at your home during these last days, you started to run like hell.