We don't know much about Scandinavia at this time. We do know from archeological finds that it was divided in Petty Kingdoms/Tribes where strongmen were subordinate to larger strongmen and probably held gold treasures for each other as a sign of respect or tribute. At the historical museum in Stockholm, it is theorised that Scandinavians acquired their gold by serving as mercenaries in the late Imperial Roman army and melted their solidus down to create collars and other jewelry.

These strongmen held local influence and lived at large farmsteads that could resemble villages. Regular pesants also lived in villages. It seems like cities or towns were rare or even non-existant during Roman times in Scandinavia. Trade and exchange probably happened at yearly markets and things. A site in Vittene, colse to where a 1,9kg gold hoard was found hidden, contains finds of at least one Roman denari silver coin and shards of pottery from Mainz, then under Roman rule.

As for cities, the first confirmed permanent settlements would be Uppåkra, Ribe, Hedeby and Birka, which all seem to arise during the late 600s or early 700s. Before that we have villages and larger farmsteads of great men (which would resemble a village).

So the Scandinavians probably served as mercenaries in Roman armies and did trade with the Romans, either directly or through other Germans.