The point here is how to convert unfamiliarity to familiarity. The first approach is to use the information of someone familiar with the city. The second approach is to familiarize yourself to the city.
If time is an issue, the first approach or finding a guide is better in my opinion. First, secure safety. Second, observe the current situation. Third, find a guide based on the observation (police, nice person, whatever). Fourth, ask for help.
If time is not an issue, e.g. traveling around, the second option can actually be quite fun. Get a map and enjoy straying around the city. :)