If you don't have a handy means of collecting StreetPass hits, that can make things difficult in Bravely Default because it affects how quickly you can unlock bonus content. However, you can add villagers to your crew even without StreetPass, provided you take advantage of an opportunity early in the proceedings.
To start, advance to the point in the demo where you receive a quest asking you to kill Adamantite. Before talking to the villager located between the spell and equipment shops, make sure that you save your progress. Then talk to the villager and you'll receive one additional villager. After verifying that your villager count has increased, talk to the Adventurer and go with the "To title" option. Load your save file and you can repeat the process as desired.
The above trick works specifically in the demo, but you should also be able to transfer any villagers encountered in the demo to the full game.