Same here, although I've gotten better at trying to show some interest, at least if I'm alone with them, because then I'm the only one who can show interest in what they're saying. I don't like being left alone with people I don't know well. I don't know how to act. Should I say something? If so, how do I keep the conversation going? When should I stop? Are they interested in what I am saying, or am I making a fool out of myself?

In Norway, people tend to not talk to strangers, so you could usually get away with not saying hello unless you end up making eye contact, then they might feel that they have to say "hello", and if they do, I feel like I have to. However, workers sometimes ask you if you need help, if they aren't too busy. I guess this is something they've been told to do, or something that's been implied. Although they might not ask you, they might still eye you, if they have nothing else to do. When, and if, they do this, I feel really uncomfortable, and scared that they'll come and ask if I want help if I look too much at something.