Hi,
I am not sure how that stepp asset would help you. I think if you just place triggers on the platforms you could then even make one fsm, with playmaker, that automatically plays a different sound clip depending on the y position (height) of the trigger. Then just copy that fsm onto every trigger (or make the trigger a prefab, of course) and place the triggers out onto the platforms. (or make the platforms and triggers into one prefab and place them in you level together)
As for playmaker working with the stepp asset. I imagine that stepp is programmed in c#, playmaker interacts very well with c# scripts in general, so you could definitely control features of stepp with playmaker. Other assets on the store also come with playmaker actions, which then makes them even easier to interact with using playmaker.
But generally if youre a true noob, I would recommend starting with far more basic things, just to get a feel for how playmaker works. Follow some basic tutorials and such.
Good luck with it!