Hi! For wild card, you can just go to the list of prompts (it's linked on the main page) and pick any prompt you like that's not already on your card. When you post, you can just say "I filled my wild card with PROMPT" :)

And fluff totally doesn't need to be romantic. If it's fluffy to you, then it's fluff. The story you mentioned totally sounds fluffy :D Light like cotton candy is how I think of fluff.

Hope this helps!