work-related discussion is a must, lunchhour small talk is pretty easy going too. knowing a topic, talk more, not knowing much, play by ear.
one point to you--- impression is that you are from (or in) UW, do not be shy, relative lack of confidence is my compatriots' nature,which should be overcome I was there doing study/RA/TA years, local undergrads are the same human being as we are. BE YOURSELF. and good luck.