Theallmightypoe
I hate to burst your bubble but, there are no rules. You can talk to whoever you want, whenever you want, however you want.
Granted, that opens up a bunch of different possibilities where the outcome can never be certain. But with enough practice you can get the right idea of how to talk to certain people in certain places.
Well... yeah, but what
works? How do you become friends with someone you don't know?
Success story: I met a general today. I knew that he had neither the time nor the energy to actually care about me, but when he shook my hand and asked where I was from, a part of me believed him. He seemed genuinely pleased to know me. He exuded charisma.
So, keeping that in mind, I went to buy toilet paper. While she was ringing me up, I let her know about a problem with one of the gas pumps. Then, before I left, I said "Have a wonderful evening," with all the energy I could muster. Her response indicated pleasure, and perhaps a bit of surprise.
I must find a way to work with this.