Xenophobia, they call it, is a fear or hatred of strangers. Even worse, misanthropy, is a hatred people.
Strangers cannot be trusted. You do not know them. They do not know you. Why would they want to help you. They could care less about you. They may even want to hurt you, steal from you, make fun of you. Perhaps, it is best to stay away from strangers. If they do not initiate the conversation, why should you. No need to be nice to strangers as they have nothing to offer. Best to mind your own business, do your job and go home to the safety and comfort of your own home where there are no strangers.
With that type of attitude, it would be difficult to want to get to know anyone. There are good people around. There are bad people around. The strategy to avoid all people will help you avoid bad people, but it will also prevent you from meeting good ones. Perhaps, it is better we re-design our strategy. Perhaps, there are ways to meet strangers in safe locations or through safe people and interact with them and select which ones are good and bad by interaction rather than by assuming all is bad. You never know what people can offer. A light hearted conversation is fine so as long as you meet these strangers in a safe location.
Secondly, don't always be the one expecting to receive. Giving advice and helping others without cost is fine. There is the idea of go first. If you are looking to see what they have to offer, they may be looking for the same. So, go first. Offer ideas, stories and information and see what you get back in return. True we do not want a leech, so do not offer more than you like. You may not get anything in return.
Enjoy the conversation at your convenience. Enjoy offering to others. Enjoy the learning process of selecting the ones you like to get to know more from others.