Sardinia (Sardegna) is a big island in the Tyrhenian Sea, between the Balearic islands and the Italian peninsula. It is one of the regions of Italy.
The same rules apply as in Italy.
There are airports near Cagliari, Alghero and Olbia. See below for some links.
There are ferry services to Caglari (south coast), Sassari (north coast), and Olbia, Arbatax (east coast). See below for some links.
Public transportation is sparse and timetables not much trustable. You definitely need to rent a car (la macchina). Beware the way locals drive racing along the narrow and bendy roads in the hills.
In the summer period, twice a week, there's a small train that can bring you from Sassari to Tempio and back. Especially for tourist. Highly recommended.
Mirto is a spirituous drink that's a local specialty.
For some serious night life, you obviously have to go to the big cities or the tourist beach places. In the small towns, the young people will get you to join their dinking game. You should join them since there's nothing else to do there anyway.