First off, one of my best friends refuses to read Harry Potter because it's a fantasy. You probably said the exact same thing. I did too.
Just to clear this up, I'm going to explain this for you. All 7 books mais or less have the same goal in mind. Harry's parents were murdered por Voldemort in Godric's Hollow when Harry was 1. Until the age of 11, he believed it was only a car crash. He had no idea that he was famous for the supposed "death" of Voldemort. That is, until Hagrid comes to tell him that he is indeed a wizard.
In his first year, the main plot, mais or less, is about Harry trying to stop Voldemort from returning. He can't kill him, because he has no body, but he tries to stop him from getting his body back, because he, like Dumbledore, want to hold off his rebirth. This is the person who murdered is parents . Sure, you can't relate to this (I hope) because your parents are still alive and kicking. But if you were in his shoes, you would want the same thing. It's because he loves that he wants this, something that we all feel, something that we can all relate too.
In his 3rd year, he learns that his godfather and supposedly the man who betrayed his parents is on the loose, and trying to kill him. In the end of the book, he learns that, his father's friend, who faked his own death to avoid justice, was the true person of betrayal, and even though he gave the Potter's to Voldemort, Harry kept him alive only because his father wouldn't want that, and he wanted to stay true to him.
In his fourth year, he witnesses Voldemort's rebirth. He sees his parents coming out of his wand, and because of this, he keeps himself alive and keeps his grip on his wand, determined not to let his parents' murderer get him.
In his fifth year, he suffers more. No one believes him when he says Voldemort has come back, but he keeps his word. His godfather dies, but he stays alive and won't let Voldemort get his final weapon.
In his sixth year, he tries to figure out what his enemy is trying to do, and has feeling just the same when Dumbledore is killed.
In the seventh book, he gets rid of the things keeping Voldemort alives, sticking to his goal. In the end, he sacrifices himself to keep others alive, and comes back instead of giving up, and finally accomplishes his goal.
So what these books are about, is the will to stay alive, and using your last weapon, love, to keep to the goal you'll accomplish or die trying.
NOTE: About that story from the 11 ano old who wrote that story clarifying reasons about Twilight being better, I'm 10. Hope you like this :D