Two scenes in, and apparently we're already ready for a montage. Marty's late for school, so he's riding his skateboard through the streets of town, hitching rides on the backs of moving vehicles. What a bad boy. Don't try this at home, kids.
Just as Marty's about to head inside his school, Jennifer (his girlfriend) warns him that he can't go in that way, or he'll get busted by Strickland for his fourth straight tardy. Let's see his feathered hair get him out of this one.