on IM your main job will be admitting patients, doing the H&P and write up, and presenting your patients on rounds...that will be the main gist of your day. know all the bread and butter IM stuff, know how to do a good, thourough H&P and know how to present a patient, first off.
i have done 2 IM rotations in the states, and it was quite different than at my school...first off, you will be on a team, and you will likely be the only med student. even if there is another student, you won't likely be fighting for patients. when i was on a team, we rotated admissions. as a student, i usually had a much smaller patient load then the residents (ie. 3 or 4 at a time), so i had time to read up on my folks and learn the pathophys.
the day will vary depending on your program...my days typically started with pre-rounds at 6 or 630 am, intake rounds at 7 and teaching rounds sometime after that. intake is where you present you new admissions from the previous day, teaching rounds would cover the other patients that you still had on service. so, after all the rounds, i would do my write ups...also, the afternoon is where you will get to do procedures. on all of my IM rotations, the students did not take call after 5 or so. so, depending on the day, we would leave between 3 and 9. typically, my days were about twelve hours long. i admitted every day, though, which could be a pain.
coming from my school, we did little in the way of procedures. even so,in my first 2 days i was doing thoracocentesis, paracentesis, LP's on IM. they were happy to show me how and walk me through it, but if you can do some before you come, it wouldn't hurt. i never had to start lines or draw blood, but if you want to learn a nurse can usually show you. basically, as a student, if the intern didn't want the procedure, or was busy, we got to do it. if i hadn't done it before, they either made me watch one, or told me to read up on it, and then do it. the attendings were always there for the crucial parts of the procedure (i think they have to be to bill 👍 ), but they sure didn't hesitate to leave while i waited to drain a few liters of ascitic fluid!!! the point is, you won't be asked to do something without being well supervised...at least you shouldn't be! the best way to get to do stuff is to automatically and enthusiastically say "YES!!" to whatever is asked of you, and to say it with a smile. you may get stuck doing some boring crap this way, but it is remembered, and a good attitude and being helpful will ensure that the resident/intern will go out of thier way to help you.
basically, be up front about what you know, and what you want to learn. every one of my US rotations has been awesome, and while i was super nervous before i started, i usually felt very comfortable pretty quickly. they do expect to teach you things, because you are a student. the key is to always be aggressive about learning, be up front about your knowledge and limitations, and be a positive person on the team. if you have a good attitude and WANT to learn, most of the time they will be happy to teach you.
hope this helps. if i left something out, or you need more info, post it and i will try to help. good luck!