We don't have too much personal experience with the "movida" in Parma, but we welcome more youthful input to add below!
For an aperitivo you can try:
Enoteca in Via Farini
Tobago Wine Bar, piazzale San Lorenzo (good selection of cocktails, you can also have dinner).
The Parma Daily publishes a daily listing of concerts, clubs, exhibits and cinema:
Parma di Notte is a facebook page dedicated to nightclubs.
http://www.metropolino.com is another site dedicated to nightlife, not only in Parma but around Italy.