Start stop timer with buzzer

Hi guys.

I'm new to Arduino modules, and I'm interested on this project planning, I saw one on you tube using a Arduino Leonardo. I have no idea what codes he's using.
The concept are arduino Leonardo, on/off switch, start button, "redy" display in the beginning the "stby" next followed by beep sound and time start counting, when hits the plate timer will stop using sound sensor plus two colour LED green and red when the power is one green led turns on until it hits it changes to red followed 2 beep sound. Then reset.

Can you please help me where to start

Regards,
Angelo

Sorry, I couldn't understand most of that, particularly "when it hits the plate".

Can you post a link to the YouTube vid you saw? That might make it easier to follow your description.

Steve

Here's YouTube link