If you are a first-year student, bring in an index card on which you have written at least one question for the experienced TAs. If you are an experienced TA, bring in an index card on which you have written at least one piece of information or advice for the first-year students.
Also, be prepared to ask questions or tell stories about your experiences in your first couple of tutorial sessions.
Be prepared to tell us something that worked well at tutorial (a success story of some sort); something that didn't work well, or that you thought could have gone better, or that you'd just like to talk about; something that you learned or observed about how students learn math. That last one can be general, but it can also be very specific.