I'm gonna echo what's been said above. No one is expecting you to know how to do these complex procedures. Half of the battle will be learning the vocabulary. Write down all the abbreviations you hear, look them up (indications, limitations, etc.), ask lots of questions, always have ins and outs and don't be afraid to ask the nurses if they haven't tallied them yet because you'll most likely be pre-rounding before they do it, and have fun. HPB is a great service. Lots of complex pathology, lots of cool cases, and also many sobering reminders that clipping the common duct during a "routine" cholecystectomy is a lot more common than not.