I'm teaching countries and nationalities to a 9 years old group and that how I started ...
STEP 1 - Practice the vocabulary with diferente games;
STEP 2 - Write on the board: "I'm teacher ... I'm from (Brazil). I'm Brazilian." Repeat the sentences several times until the students understand it. Then, write: "Where are you from?". Repeat question and answers. Make the question to the students and let them ask the teacher as well.
STEP 3 - Make small papers with names of different countries on it. Be sure you did two papers of each country. Give the papers to the students and they have to find their pairs as soon as they can acting the dialogue: Hello / What's your name? / Where are you from? - The first pair to complete the quest is the winner.
Variation: Encourage students to say the country and the nationality, practicing the srtuctures: "I'm from ..." and "I'm ..."
The link bellow is a worksheet suggestion. Hope you like it!
Tks ... Teacher Carol