Button Triggers

Just a bit to get you started. I created 4 slides with first slide being my Main page, and three other slides being my content slides I navigate to from the Main page.

1. Create a custom variable (eg. "audioComplete") and set it to "False".
2. Create a trigger Play audio when the timeline starts on this slide if "audioComplete" = value False. 3. Create another trigger Adjust variable Set "audioComplete" to value True when audio completes.
4. Create three separate triggers Change state of button to Normal when the audio completes. 
5. Create three separate triggers Jump to slide when the user clicks button

First three triggers will ensure that the audio is only played once. Upon returning to the Main page, the audio will not play as condition in second trigger has changed by an action in third trigger. I suggest having "Resume saved state" selected in the Slide Properties for this type of training so the buttons visited state are retained upon revisiting the Main page.  

I attached a simple .story file to demonstrate all steps above with the buttons showing locked, unlocked and complete states. I am not sure if this is exactly what you are looking for but please feel free to ask for any further assistance.