Perugia is a city in Italy. Visit the historic center, if you have the oppurtunity!
For all directions you should get to Ponte San Giovanni, there is a driveway on the E45, which splits soon into the different directions.
To Ponte San Giovanni you can either walk (it's about 1 hour) or drive with the bus, but you should try to hitch there, it's quite easy. Just go to the Parcheggio Auto 1 at the Via Tancredi Ripa di Meana, east of the city center. You'll find the Parcheggio shortly after the Via Tancredi Ripa di Meana ends being a one way street heading south. From there you'll get picked up fast.
In Ponte San Giovanni you may either wait at the Via Manzoni which leads to the driveway or even right behind the underpass (only for heading NNW, NNE, NE, E, see below!), just be careful, they're driving fast there. Someone will pick you up fast and bring you to some gas-station or sevice-area.
The driveway for heading South towards Torni or Roma (E 45) and North-West towards Firenze is in front, the driveway for heading North-North-West towards Ravenna (E45), North-North-East towards Gubbio (SR 298), North-East towards Ancona (SS 318) and East towards Assisi (SR 147) or Foligno (SS 75) ist right after the underpass.
Be clear, where you want to go! The Highway is splitting soon after the driveway and it can happen that the drivers take you in the wrong direction if you are not.