Another possibility is that the main character is the wizard who runs the pizzeria. He could be an old friend of Dumbledore's. And he hires some Hogwarts students to help him out. Fred and George Weasley might be interested in working there to try out some of their pranks on the customers, which would make for an interesting story.
The plot might involve a wizard who opens a pizzeria using magic to create unique pizza - for example, the dough rises with a simple spell. Harry Potter and his friends could visit this pizzeria during their free time. There could be some sort of mystery around the pizzeria too, like strange disappearances of pizza slices which turn out to be the work of a mischievous house - elf.
It might be a pizza chef and a food critic. The critic comes to review the pizzeria. The chef is initially nervous but the critic is impressed by the food. As they talk more about pizza - making techniques and flavors, they develop feelings for each other.
Draco could start as his usual haughty self, looking down on the pizzeria work. But as he faces challenges like dealing with difficult customers or learning to make pizza properly, he could gradually become more humble. For example, when a customer complains about the pizza being too cold, instead of his usual snappy retort, he tries to fix the problem and learns about customer service.
One idea could be that Draco Malfoy, for some reason, has to work in a Muggle pizzeria as part of a new Ministry of Magic initiative to promote understanding between wizards and Muggles. Harry Potter could be a regular customer, and there could be all sorts of awkward and comical interactions as Draco tries to keep his wizard identity a secret while serving pizza.
Neville Longbottom could be a main character. He has always had the potential for great things and in a world without Harry, he would be likely to step into the spotlight. He has the courage and the connection to Hogwarts that could make him a central figure in the fight against evil.
Hermione could be there. She would be eager to study the different magics and books in Tamriel. Her intelligence would help Harry navigate the new world.
Hermione could be a main character. As a very intelligent witch, she might assist Harry in his teaching, like helping him prepare complex lessons or providing additional knowledge to the students. For example, when Harry is teaching about ancient spells, Hermione could offer insights from the books she has read.
Hermione could be one. She could come to Degrassi to help Harry. She'd be really good at handling the academic side of things there, like helping students with their studies. And also, she could use her magic knowledge to figure out any magical mysteries.
Hermione could also play a role. Given her intelligence and love for learning, she might take an interest in accounting to better manage the finances of the various causes she's involved in, like the Society for the Promotion of Elfish Welfare. So she could be a main character or at least a supporting one in this fanfiction.
Obviously, Harry Potter himself could be a main character. He could be the one who is initially reluctant to participate in a dance event but then discovers a new passion for it. Hermione could also be a main character as she might be the one researching the history and significance of different wizarding dances.