Uhumm. I'm not really good in this yet, can you tell me please how to make the trigger thing?
You need to have a play with Contrust for a bit more to understand.
There are different types of events.
One type of event is a trigger event.
This will fire once when the trigger thing happens.
In your case the on mouse click is a trigger event.
This should only play your sound once when you click
But the sound will always play to the end once started
If the sound is a long sound or is a short sound with a long reverb
when you click lots of times you will have lots of overlapping versions of the sound
this will give you phase, distortion, and gain issues.
To fix, in this case, your event should be
On mouse click
Stop Sound "my sound"
play sound "my sound"
this will stop the sound if it is playing before playing it again.
so there is only ever one of the sound playing at a time.