Sims 4 machinima help. (Not sure where to put this)

I don't know how you can solve what you are looking for. I use Filmora (not free, but not expensive). They have loads of elements that can be added to your film, but they are more like graphic overlays, not really a smoke cloud interacting with your characters.

I hardly used those effects myself yet, but here is one example, see at 5:40
https://youtube.com/watch?v=4CVYqgcAluY