Student or Learner
I am not sure if my sentence sounds natural. Would you please correct my mistakes?
The teacher had to shout angrily over the clamour of the class before it lapsed into silence.
It's grammatically correct but it doesn't sound very natural. In addition, in BrE, we would probably refer to the class as "they" because it means "the students in the class". Unless you need to specify that the teacher was angry, I would probably just stick with "shout". We don't use "clamour" as a noun very often. You're more likely to hear something like "The crowd was clamouring for the next band to come on stage".
The teacher had to shout over the noise of the class before they finally fell silent.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.