This lesson has lots of information about Pentecost, consecration, Mary as the New Eve, etc. but what I would start with is the spreading of the light activity on page 9.
You’ll need cupcakes and candles, a dark room, and a storyteller to explain how the light of faith started with Jesus, the Great Light and now spreads everywhere through the actions of the Holy Spirit, working through us,
This is a great activity to do with another family and, conveniently, you’ll already have cake and candles to celebrate the birthday of the Church!
From this core of the lesson, go ahead do the other stuff with your older kids, but starting with this foundation of celebration is the perfect way to both teach and say thanks to the Holy Spirit for His role in our lives!