Novel: A french teenager runs away to fulfill his dream of becoming an actor in L.A.

That's the premise, not the logline.

Logline needs to identify conflict. Where does conflict arise from? Act I to Act II?

How about something like "To prove to his family that he's not worthless, a French teenager goes to LA to become an actor."

If you don't like that, you have to think about what it is that drives him to go to LA. What is he trying to prove, and to whom?? If he fails, in what specific way will that affect him?

Maybe he's doing it to get the girl he's always loved, and the girl is determined she'll only ever marry a movie star. Or maybe he's doing it to prove to his?dying and hopeless?little brother that miracles?do happen if you try hard enough.

>>>Well, the story isn?t about him becoming an actor especially,

But that's not what the logline says.