Hi! This is answered in the FAQ already, but let me know if you need more clarification than this :)
How about fan comics about something else I like? Yes, if they're yuri.
How about fan comics genderbending male characters into yuri? It's cool if that's what you want to make, but for this jam, maybe consider using the characters you like as inspiration for new original characters instead. Trans and nonbinary headcanons are totally cool though!