IMO, you shouldn’t feel like you need to do anything outside of your comfort level; just follow basic social norms - if someone says hello, you say hello back and that’s all that’s expected. If you genuinely care what someone did on the weekend, ask. If you don’t care, don’t ask. I’m very friendly with people in my office, but not at all with others in my building. I don’t know them and don’t care too, unless/until we have to work together on something. Those people get a head nod if we pass in the hall, but I often carry a paper or folder with me so i can pretend to read it to avoid looking at people as we pass.