If you want to do a B2 listening task about the tradition of Bonfire Night in Britain today, you can follow this link to LearnEnglish, a section of the British Council website. The video alone can also be clicked directly below:
Finally, you can also read this current report from The Sun about some violent incidents on Bonfire Night yesterday, when minorities of "yobs" (hooligans) threw fireworks at police officers and firefightes, and a "lad" (boy) was stabbed in Merseyside, near Liverpool. This report is a good example of sensationalist journalist style, the vocabulary is very snappy and colloquial, but it should be accessible to B2 students.