Answer:
Of course, these are my opinionated responses so they might differ from what you're learning.
1. In a school environment, its more friendly and not really professional orientated. I would break the moment of silence and approach the student. Whilst doing that, having a eye contact and a smile on your face giving the impression that you're a friendly person. Some unfavorable responses would not having good eye contact and having a monotone voice.
2. As this is a professional environment, connections matter the most. Its always great to make relationships with your co-workers. Having a friendly attitude and open to communications with those people around you are very important. Introducing yourself to those co-workers with a great attitude and eager to work for the company always leave a great impression. Unfavorable responses are like the 1st response. Having a monotone voice, poor eye contact, and a terrible attitude.