When Zack takes Laney to the beach, you see her on the beach with her art book just before she goes to play volleyball. When she leaves the beach and walks back to Zack's car, she doesn't have her art book with her.
When Zach looks at his college acceptance letters, the inside addresses shown are those of the colleges. In a real letter, the inside address would be that of the recipient. The school's address would be shown elsewhere on the letterhead.