I’m really passionate about the language and I want young children to be educated about other cultures and languages.

I would start by teaching them basic things like colours and the days of the week, then continue with simple sentences in the present tense like « Je m’appelle [their name] » and « J’aime [certain food or anything] » This would give them basic skills that they can continue to develop in secondary school and give them a one-up to see if they would want to pursue the language in later years of education.