He might meet some former Death Eaters who are trying to redeem themselves. These Death Eaters could be seeking Harry's forgiveness or trying to make amends in some way. Harry's encounter with them could be a complex and interesting part of the story. He could also meet wizards from other countries who have heard of his deeds in the war and are interested in collaborating with him on some magical projects or just sharing their own magical traditions with him.
Perhaps Harry meets magical creatures that are rarely seen by wizards. Since he is out exploring after the war, he might stumble upon a group of centaurs who have their own unique wisdom about magic and the future. He could also encounter veelas, and through his interactions with them, learn more about the different cultures within the magical world. There's also a chance he meets other young wizards who are on their own adventures, and they form a sort of traveling group together.
He could meet new witches and wizards from different cultures. For example, he might run into a powerful African wizard who has unique magical abilities related to nature magic. Or he could meet a Japanese witch who specializes in charm - making that is based on ancient Shinto beliefs.
Perhaps he leaves to explore the Muggle world. Harry has always had an interest in Muggles. After the war, he realizes he wants to experience life without magic for a while. He could go to university in a big city like London, study a Muggle subject like history or literature. He'd make new Muggle friends and try to fit in, all while still having his magical abilities hidden, which would add an interesting dynamic to his new life.
Ron could also play a significant role. He might be torn between his loyalty to Harry and his family and the wizarding world. He could join Harry on his travels for a while, or he could stay behind but still be in contact with Harry, sending him care packages of wizarding treats and useful items.
He could meet other famous wizards from different countries. For example, he might run into Nicolas Flamel, who has been traveling around the world. Flamel could share with Harry some of his vast knowledge of alchemy and magic that has been passed down through the ages. This encounter could give Harry new insights into magic and its potential uses.
It could be Ron. Maybe he starts to feel that Harry has changed too much after the war and is no longer the friend he once knew. He might be influenced by outside forces or his own insecurities. Another possibility is Hermione. If she gets too involved in the new Ministry politics and starts to believe that Harry's actions are not in line with the new wizarding order, she could turn on him.
There's a chance he meets a group of nomadic magic - users. These are people who travel across the universe in search of new sources of magic. They could introduce Harry to different forms of magic that are not based on the traditional elements like fire, water, earth, and air that he's used to on Earth. Instead, they might use things like starlight or cosmic energy as a basis for their spells.
Harry might meet some American wizarding families that have long - standing traditions different from the pure - blood families in the UK. These families could introduce Harry to new forms of magic and social norms within the American wizarding community. He could also meet American Muggle - born wizards who have their own unique stories of discovering magic in a different cultural context compared to what he's used to.
One possible storyline could be that Harry leaves to explore the wizarding world outside of Britain. He might go on a journey to discover new magical creatures and spells that were previously unknown to him. Maybe he wants to find a place where he can truly be at peace after all the chaos of the war.
He'll most likely meet Bella Swan. Maybe he stumbles upon her in the forest and she's initially very wary of him, but then they start to talk and find they have some similarities in terms of being outsiders in their own worlds. He could also meet the Cullens. Edward might be intrigued by Harry's magic and Harry could be fascinated by Edward's vampire abilities.
He could meet French pure - blood families who have their own long - standing traditions. For instance, there might be a family that has a special connection to a particular magical forest in France. Harry might also run into French wizards who are experts in potion - making, as France is known for its fine potions in the wizarding world.