Bea was 5 months old on her first Bonfire Night, we closed the curtains and did not react to the noise, Pup's tend to look at the Humans to react first and then react to that.
My girls breader got all the pup's used to load noises before they came home, I remember going to visit her and the radio was very load and all the pup's where acting as normal.
Of course it could just be the work her Breader did with the Pup's, but Bea might give one bark and then go off to sleep!
Good luck.