Who Knows the Name of a Nickelodeon Short Cartoon from around 2002 to 2004?

There's this kid on top of his barn(or house roof) reading a comic book that had Danny Phantom on one of the covers. Then like 2 aliens came down, started to attack. After a bit a female alien(I think. Could have been some kind of weaponry instead) came down and captured the attackers. He went with her up into space and he was enrolled in a school full of aliens. I remember one scene where he's taking a Gym Cl and they're using like super-suits(or some kind of shoes).