Generally Trainees help out with and learn about whatever their co-workers are doing.
Above all your task will be to accompany your international colleagues to the emergency calls. Depends on the country and your abilities but you are meant to assist the care or even to treat patients by yourself while getting assisted. It can include all aspects of keeping medicines ready, intubating, assisting in transport preparation and more.
You may get also some basic tasks that just have to be done like bringing out the garbage.
Note: You will also get different tasks at your accommodation, e.g. cleaning up your room.
Your accommodation is no hotel, so it’s natural keeping your living area tidy or helping with the meals.
In regards to the 24-48h/week we highly recommend you discuss this with the host prior to your visit as this may be important for your travel plans.