My daughter and a friend stayed and did that after the program had ended. Travelled by train, stayed in hostels (which can be super-nice in many countries!) and AirBnBs, had a backpack with detachable daypack to avoid pulling/carrying suit cases through train stations and local streets.
The backpack was designed for travelers to “live out of” so it could be unfolded, with various compartments, that one didn’t have to unpack each time.
The hostel stays were among her favorites, because of the community aspect - meeting people from all continents, all with similar mind set, sharing stories.