The books I think were also saying some sort of code. There were numbers under the letters. I think there is a code there to decipher, but I don't know if anyone will.
If you use a reverse asymmetric cipher and then run every odd digit through a modified Grover's algorithm, it reads "Help, I'm being held prisoner behind an Italian restaurant".
(wads paper, tosses it away) ...Ehhh, I'll keep trying.

Also, Starlight appears to be eating Doritos (though they could be generic store-brand knockoffs) and watching
Zootopia on Twilight's laptop.