If you wish to add a sound effect, say a dog barking from your left can you do this on the main audio track of do you have to do things like adding a track & then having to pan that new track?
You can actually do both depending on what you are hoping to obtain in the end. If you add to main audio track it will however interfere/cut your main audio stream. Therefore best to add new track, insert sound effect and pan it to left. If need be you can change its volume with an envelope to make it get louder for example as the effect unfolds...lots of options as always!!