Mikey might be a character created to tell a story about Pop Rocks. He could be a fictional child used to illustrate the appeal or novelty of these candies. For example, he could be a curious and adventurous little boy who wasn't afraid to try new things, like Pop Rocks, which were quite different from other candies at the time.
You can start by finding a reliable source to get the novel. Then, set aside dedicated time each day to read and focus on the story without distractions.
April and Casey might also be part of this fanfiction. April could use her reporting skills to try and figure out what's going on with Mikey's mutation, and Casey would be ready to fight any new threats that come along because of Mikey's changed state. Also, Splinter, as their sensei, would be guiding them all through this difficult time, providing wisdom and training to help Mikey control his new powers if he has any.
I'd suggest checking out online bookstores like Amazon. Sometimes, they have a wide range of light novels available for purchase or reading through their Kindle service. Also, keep an eye on fan forums and communities related to Cote, as members often share where they found the light novel.
Well, a good way to start is to look for discussions online. Many fans share where they picked up the manga after the anime. Also, check the official manga website for any guidelines.
Fanfics like'mikey x raph fanfic' are really interesting. They give fans the opportunity to expand on the existing relationship of the characters. In this case, it might explore how Mikey and Raph support each other in ways that the original source material doesn't fully show. It could be a story full of humor as Mikey cracks jokes and Raph reluctantly smiles, or it could be a more serious exploration of their bond during difficult times.