Hi SwanOwl, Welcome to the Forums,
I think Niagara particles will be a great fit for simulating the spores.
Some of the Niagara features are demonstrated in the Content Examples project.
Also I noticed this ‘Particle Wind Control’ asset in the permanently free collection. It uses the previous particle system ‘Cascade’ but could be worth a look.
So I’d start with the Niagara Particles ↔ Wind interaction. (You’ll want to create a way to control the wind via keypresses so you don’t pass out when trying to test it. 
)
Getting fan input in UE is an interesting problem. Maybe the solution involves an arduino. To be honest the idea of festival-goers blowing strongly at a specific object is off-putting. (Going to chalk that thought up to post-covid trauma 
) An alternative idea would be to have them rotate something, and the rotation the object translates into rotating the wind direction, plus maybe a slider to control the wind speed.
Let us know how it goes!