That sounds somewhat similar to something I'm doing in September. Coincidence! lol I would write down the proper care of bettas, myths, as suggested above, and some cool facts, like how they breathe air, the fact that they were bred to fight for entertainment (and the fact that it is cruel and you should never put two male bettas together!) how different they are from the wild specimens, etc. If you want to get more in-depth you could write about proper tank maintenance and the nitrogen cycle, but I don't know how long and boring you want your article to be. Just kidding! I'm sure it won't be boring, and all the science nerds would love the nitrogen cycle explained. Good luck!