Le petit prince (1943)

Translated into about 600 languages, a record for any book apart from the Bible, so it is almost certainly available in the one you are studying. The French original is written in plain, short sentences, which is why it is such a common first novel for French learners in particular. What keeps adults reading is what it says about grown-ups: the fox, the rose and the businessman counting stars are aimed at you as much as at any child. Because so many readers already know the story, you can follow the plot and give your full attention to the language.