Please help with Japanese phrases for extra situations while working hall baito at Sushiro

Hi. I recently started a baito at Sushiro, working in the hall. But my Japanese is very basic, so I feel stressed at work because I do not know what to say, not even to customers, but also on the microphone or in general situations.

If anyone here has worked at Sushiro, could you please share some phrases that you used during work?

For instance, when you take the micro, do you say something on it or not? Do you say on the micro when it is time to finish your work?

I know phrases like 失礼します or かしこまりました, but I need something for extra situations with customers, like when they receive the wrong order. What should I say to them? What should I say to the micro?

I would be very grateful for any help. I want to be effective at work and not be so stressed.

Thank you.