How do I deal with the people of karachi?

I am a guy. I have no proper skills and do not know how to deal with so many people constantly lying and trying to get money out of you. This is a big issue in karachi and not just dukandar but sometimes friends, relatives also lie and can cause you harm. My question is to those who know how to properly deal with these kind of people, how can i learn to not fear these people, deal with these people easily and live in peace?