Kavala is a city in Greece.
Hitching out
East towards Xanthi, Komotini, Alexandropouli, Turkey...
Get bus #3 or bus #11 out of the city as far as the cemetary (or as far as it goes in that direction). This is Amerikanikou Erythrou Stavrou (road 2) and it goes straight onto the E90 in the direction of the cities listed above.
Hitching in
You can get dropped off at the highway exit next to Kavala, whih is good because it means you don't have to find a lift going exactly to that place, but can also accept any ride going past it. It is an easy, although rather long walk down the winding road, with cars zooming past you. It is downhill all the way though, and the road leads straight into the city centre. You can even try sticking your thumb out as you walk.
Places to avoid
Accommodation and Sleep
There are abundant wild camping opportunities in the woodland to either side of the road down into Kavala. This seems like a city where sleeping out would never be a problem.
Other useful info