He might meet the future versions of his friends like Hermione and Ron. Their children or grandchildren could be there, and they might have different personalities and magical skills compared to their predecessors.
In this fanfiction, Harry Potter visiting the future would be a wild adventure. He might discover that some of the old magical artifacts he knew have new uses or powers. He could also encounter threats that are different from what he faced in his own time. For example, there could be a new dark wizard or a group of dark wizards who have found a way to use modern technology combined with magic in a dangerous way. And his own legacy in the future could be a big part of the story. People might see him as a great hero or there could be some who misinterpret his actions from the past. Harry would have to navigate this new world while still holding onto his own values and experiences from his time at Hogwarts and during his battles against Voldemort.
Harry Potter steps into the travel shop. It has a musty smell, but it's filled with magic. There are shelves of spell - bound travel guides and potions for travel sickness. The shopkeeper, an old wizard with a long beard, greets him. Harry starts looking around, intrigued by a pair of flying boots on display.
One possible fanfic could be where Harry visits Uncle Dudley after the war. Maybe Dudley has had a change of heart and they start to build a tentative relationship. Harry could be there to show that he has moved on from their past differences and is willing to give Dudley a chance to be part of his life in a new way.
He could meet his future children, if he has any. They would likely be powerful wizards or witches with their own adventures. Also, he might run into the future versions of Hermione and Ron. They would probably be in important positions in the wizarding world, like Hermione might be a headmistress at Hogwarts or something.
He'd first have to get used to the new technology. If there are new magical devices, he'd need to learn how to use them. For instance, if there are advanced wands with extra functions, it would take him some time to figure them out.
He might be shocked. In fanfiction, the future could be full of strange twists. For example, if his friends' children are involved in some wild adventures that are very different from what he expects. He would probably be confused at first, then curious to understand how things got to that point.
Harry would rely on his basic values. His loyalty and courage would still be his strong suits. He might join a group of young wizards who are working on some noble cause in the future magic world. Through interacting with them, he'd gradually understand the new rules and customs. For example, if there are new dueling regulations, he'd learn them in the process of joining friendly duels.
One interesting fanfiction could be where the dragon is a magical protector of Harry. It might show up when Harry is in great danger, like during the final battle against Voldemort. The dragon could use its fire and strength to fend off the dark wizards.
In this fanfiction, Harry might see a world where magic has evolved in unexpected ways. For example, there could be new spells that are far more powerful and complex than the ones he knew. He could also find that Hogwarts has changed, perhaps with new buildings or different teaching methods. And maybe he would encounter descendants of his friends, who have their own unique stories to tell.