Students usually work in groups or pairs.
As preparation it can be useful to put up pictures of the various countries on the board.
After you practice and teach the dialogue the students pick a country and fill in the dialogue about what to do there.
Then one member of the group comes to the teacher and has the dialogue with the teacher. They bring their groups passport card. After the dialogue the teacher writes the name of the country on the back of the card and the student returns to their group. They select a new distination and go again.
If you want offer rewards I'd do stickers after completing half the dialogues or use random point cards and make the activity competitive. You could also do character races on the board. Their character advances after each dialogue so they can see which groups are furthest ahead.