Well, one possibility could be that Harry goes to France to study at Beauxbatons. He might make new friends there, like a French wizard who introduces him to the unique magical traditions of France. He could also get involved in some mystery related to an ancient French magical artifact.
In a 'Harry Potter lives in France' fanfiction, perhaps he moves there to escape the fame in the UK. He starts a new life in a small French wizarding village. He might learn about different types of French magic spells that are not commonly known in the UK. He could also meet a love interest, a French witch who has a different perspective on magic compared to his British friends.
Maybe in this fanfiction, Harry is sent to France on a secret mission by the Order of the Phoenix. While there, he has to adapt to the French wizarding society. He could encounter some dark wizards who are causing trouble in France. He has to use his skills and knowledge from Hogwarts, along with learning new French magical techniques, to defeat them and protect the French wizarding world.
There could be an old French wizard named Alphonse. He might be a mentor to Harry, passing on his knowledge of ancient French magic. Also, a young French witch named Celeste could be a main character. She and Harry could develop a friendship or more, and she could be part of Harry's new life in France, like helping him understand the French magical education system which is different from Hogwarts.
Well, perhaps the plot could be that Harry is on the run from some dark forces and the trunk becomes his only safe haven. He might have enchanted it to be much larger on the inside, like the Room of Requirement. Inside, he could have all his essentials, his school books, his owl, and a little bed. He uses magic to keep it hidden and moves from place to place without being detected.
Well, one possibility could be that Harry discovers a hidden magical island. He might find new magical creatures there and learn unique spells to survive. Maybe he builds his own little wizarding home on the island.
One possible plot could be that Harry is turned into an animal, like a stag, which is his Patronus. He then has to navigate the wizarding world in this new form. He might use his animal instincts to discover hidden secrets or evade his enemies. For example, he could sneak into places unnoticed as an animal, which he couldn't do as a human. He might also communicate with other magical animals in a way he never could before, and they could help him on his quests.
It could be that after a great battle, Harry Potter decides to retreat to the woods to heal both physically and mentally. While in the woods, he stumbles upon a hidden magical community that has been living there in isolation for centuries. He then becomes part of this community, sharing his knowledge of the outside wizarding world and learning their unique ways of magic which are deeply connected to nature.
Maybe Harry discovers a hidden magical community in the forest. He could learn new spells from the forest creatures and use them to protect Hogwarts later.
Well, in this fanfiction, Harry might be drawn to Australia because of some hidden magical lore. He could discover ancient Australian magic that is different from what he's used to in Europe. He might even make new friends among the Australian wizarding community and learn their ways of magic, which could be more in tune with nature compared to the more formal magic in Britain.
Well, it could be that Harry goes to France on a secret mission. Perhaps he's following a lead on a dark wizard who has ties to France. In France, he might have to adapt to different magical customs while trying to complete his mission.
Maybe Harry moves to France for a new start. He could discover new magic there, meet interesting French wizards and witches, and perhaps study at a French wizarding school. He might also face some cultural differences and challenges in the magical world.
The plot could involve Harry exploring the castle's secrets. Maybe he discovers hidden chambers filled with ancient spells and artifacts left by his ancestors.