Honestly, there's no definite record that indicates Jack Kirby went to Comic Con. Maybe he did, but it's not something that's been prominently documented or widely discussed in the comic community.
Definitely Naruto. Naruto would be curious about Kirby's abilities and would probably want to be friends right away. They could have some fun training sessions together, with Kirby showing off his inhaling skills and Naruto his new Rasengan variations. Also, Sakura might interact with Kirby. She could be initially a bit skeptical but would come around when she sees how Kirby can be helpful in medical situations by using his powers to quickly gather medicinal herbs or supplies.
In such fanfiction, Kirby is often depicted as his cute, round self, but with a more tender side when it comes to his feelings for Jigglypuff. He might use his unique abilities to protect or impress Jigglypuff.
Ruby could be a great friend for Kirby. They both have a sort of innocence about them. Ruby's love for adventure and her kind heart would make her open to befriending Kirby. They could go on adventures together and Ruby could help Kirby understand the world of Remnant.
It has likely influenced the franchise in terms of art direction. The Japanese graphic novel's art style may inspire future Kirby games or other media in terms of character design and scenery. For example, if the graphic novel has a particularly cool way of depicting Dream Land, it could be incorporated into a game.
Well, in such a fanfiction, game Kirby could introduce anime Kirby to the more traditional power - ups from the games. Meanwhile, anime Kirby could show game Kirby some of the unique storylines and character interactions that are common in the anime. Maybe they would have a friendly competition to see who can inhale and defeat enemies faster. It would be a really interesting crossover with a lot of potential for fun and adventure.
Another place to look could be at anime and manga conventions. There are often booths selling various light novels, and there's a good chance you might find Kirby Light Novels there. Also, if you know any fans of the Kirby series, they might be able to give you some tips on where to find these novels.
First, think about the plot. Decide if it's going to be an adventure, a mystery, or something else. For example, if it's an adventure, figure out where Kirby is going and what he'll face. Then, create some interesting characters, even if they are just new enemies for Kirby to battle.
You can start by looking on fanfiction websites like Archive of Our Own or FanFiction.net. Just use the search term 'Kirby Hurt' and you'll likely get a list of relevant stories.