How to apply for the permit of stay
The visa issued by the Italian Representative is a permission to enter Italy. To stay for the duration of your studies it is mandatory to apply for the residence permit (permit of stay).
A residence permit/permit of stay is not required for business, tourism, short visits or study, provided that the stay does not exceed 3 months. EU nationals do not need a residence permit to stay in Italy.
More information here: http://wcm-3.unipv.it/site/en/home/student-life/documents-required-for-your-stay.html
On this webpage: http://questure.poliziadistato.it/stranieri/?mime=1&lang=english you can check when your permit of stay card is ready and you may collect it form the Questura