Beautiful Creatures is narrated by a sixteen-year-old guy. He's very well-read, but he doesn't use a big vocabulary or ponder esoteric thoughts or anything like that. Actually, Ethan's voice is readable and super accessible.
You might find a few roadblocks in the language department, but it's nothing you can't conquer with a little help from Shmoop:
(1) A few of the other characters have a thick Southern accent, but it's usually easy enough to understand, especially if you sound it out.
(2) Once Lena's mythology starts getting explored more, more unfamiliar words and terms come out. But don't you worry; they're all defined for you within the text. (Plus you can just check our Character pages if you get lost on who's who and what they do.)
(3) Some of Lena's family's mystical chanting is done in Latin, but all the important stuff is translated for you.
So once you get over some of the stumbling blocks of language, you can sit back, relax, and enjoy the magic.