What happens at the Questura?

The receipt proves you applied and are legally in Italy while you wait (MUR circular).
Bring your passport, receipt, appointment letter, originals of what you copied, and passport photos (carry four). They take photos and fingerprints.
Track progress on the Polizia di Stato website with your receipt codes; information line 803160.
Conferences abroad: PhD students travel early. Check the current Polizia di Stato rules before any trip on the receipt alone, and plan first year conference travel around your card.

This page explains official rules in plain language. I am not an immigration adviser and I do not give visa advice. For that, always use official government sources. Rules change: confirm with your university, the embassy and VFS before you act.