It could be that they start the story in an excited manner. Finn jumps up and says 'You won't believe what we've got to tell you!' Then Jack adds 'Yeah, it's a really wild story.' And then Finn starts with something like 'There we were, in the middle of nowhere, when suddenly...' They build up the anticipation before getting into the main part of the story.
They might start by sitting down in a cozy place, like under a big tree. Finn could begin with 'Once upon a time...' which is a very common way to start a story.
I don't know the specific story they tell. It could be an adventure story about their exploration in a magical land, full of strange creatures and hidden treasures.
Maybe they would tell a story about friendship. Since they are friends in real life or at least colleagues in the acting world, they could create a story of two friends going on an adventure together, facing challenges and helping each other out, like exploring a magical forest filled with all sorts of amazing creatures.
They might tell a spooky story, considering Finn Wolfhard has been in some horror - themed works like 'Stranger Things'. Maybe it's about a haunted house or a mysterious creature in a small town.
Well, it could be a story about a group of kids who discover a hidden portal in their neighborhood. The portal leads to a parallel world where everything is both familiar and strange. Jack Grazer and Finn Wolfhard's characters might be the leaders of the group, trying to find a way back home while also exploring this new world and its rules.
Perhaps a story about a magical circus that only appears once every hundred years. Finn and Jack's characters stumble upon it while on a hike in the woods. Inside the circus, there are all sorts of strange and wonderful acts. There are acrobats who can fly without wings and magicians who can make things disappear into thin air. But as they explore further, they realize that there is a dark secret behind the circus's magic. They then have to figure out a way to either expose the secret or save the circus from disappearing forever.
I'm not sure specifically about Finn and Jack Harries gay fanfic. However, fanfic in general can be found on various fanfiction platforms. You might want to check websites like Archive of Our Own (AO3). They have a wide range of fan - created works, but it may take some searching to find something related to Finn and Jack Harries in that context.
The Finn Maccool story is a famous Irish legend. Finn was a great hero. He was known for his strength and his leadership of the Fianna. He had many adventures, like fighting giants and protecting his land. His tales are filled with magic and bravery.
It could start with Finn exploring a strange new area in his world and suddenly stumbling upon a portal. When he steps through, he finds himself in Fionna's world and right in front of her. There's an immediate sense of confusion and curiosity from both of them.
Another way to start is by presenting a problem or a mystery. Like 'A strange box was found in the attic, and no one knew what was inside. This immediately grabs the attention and makes people want to know more about the story.
Another option is to look at the related videos on YouTube. Sometimes, fanfic writers promote their works through video descriptions or even make videos about their fanfics. Although it might take some time to sift through, it could lead you to a great fanfic about Jack and Finn Harries' sister. Also, don't forget to check the comments section as fans might be discussing other fanfics there as well.