new office for the holiday

I recently moved positions and including changing offices. By switching position, I have missed out on signing up to participate in all of the holiday events. I also am now sharing an office space with 3 other people, who were not excited to have one more person in their space, and I am not part of their department so a lot of outsider type feelings happening. I came from a very social and inclusive area were everyone was made to feel welcome even if they were from outside of the department. I am wondering if I should maybe get a little something for the individuals, or maybe bring in lunch for the group for the holidays. Or maybe I should just go hang out someone else when they are doing their holiday events, since I have not been invited to participate. Your thought?