In such a fanfiction, Harry could discover the world of Greek mythology. Maybe he'd meet demigods and learn about their powers. He might also compare his magic from the wizarding world with the powers of the demigods at Camp Half - Blood.
You can try fanfiction websites like FanFiction.net or Archive of Our Own (AO3). They have a vast collection of fanfictions, and you might be able to find the 'Harry Potter finds Camp Half - Blood' ones there. Just use their search functions and type in relevant keywords.
Another theme is the discovery of new magic. With the merging of two different magical concepts, fanfiction often features characters exploring new forms of magic that are unique to this combined universe. For example, spells that are a combination of Hogwarts magic and the powers of the demigods. This makes the stories exciting as readers get to see something new and different.
Yes, there are quite a few. You can find them on various fanfic websites. Some might focus on crossovers between the two universes, like a character from Harry Potter ending up at Camp Half - Blood and having to adapt to the new environment and its rules.
Well, he might be really confused at first. The magic in the Camp Half - Blood is different from what he's used to at Hogwarts. He could make some new friends, like the demigods there. Maybe he'd learn new combat skills too.
One interesting plot could be Harry Potter arriving at Camp Half - Blood and being mistaken for a demigod at first. He then has to prove his own magical abilities which are different from the demigods'. As he stays, he starts to learn about the Greek gods and their ways, and he tries to find a way to combine his Hogwarts magic with the powers and knowledge at the camp. Maybe he could even help the demigods in a battle using his unique spells.
There is 'A Half - Blood in the Wizarding World'. This fanfiction delves deep into the character development of the protagonist who has a connection to both worlds. It's full of mystery and magic that keeps you hooked from start to finish.
In a fanfiction, the interaction would be full of surprises. Harry Potter and his friends would bring their own set of values and skills. Harry's sense of justice would align well with the demigods' heroic nature. Hermione would be like a walking encyclopedia, impressing the demigods with her vast knowledge. The demigods could teach the Harry Potter characters about their unique powers. Percy Jackson might show Harry how to control water in a different way than magic. There could also be some misunderstandings at first. For instance, when Harry first uses magic, the demigods might think it's some kind of dark power. But as they get to know each other better, they would form strong alliances and friendships.
One common theme is the clash of cultures. The magical world of Harry Potter and the demigod world of Camp Half - Blood have different rules, so when characters from both worlds interact, there's often a struggle to understand each other.