Destination Earth by Ali Sparkes

Description

Imagine you are the only survivor from another planet. You’ve spent ten years on a spaceship learning how to be human, and now the end of your journey is in sight… All you have to do is land safely, convince the earthlings that you’re a real teenager, and start your new life on Earth. No problem.

Except that the killer alien responsible for wiping out your people has hitched a lift. And it’s just a matter of time before it starts on the human race…