If you find logic puzzles interesting, take a look at "Games for Your Mind: The History and Future of Logic Puzzles" by Jason Rosenhouse. There's a whole chapter on Smullyan and his Knights and Knaves problems and is a generally good guide for getting into formal logic.
The part I enjoyed the most in the book was "The Empuzzlement of Gödel's Theorems" that uses a twist with Knights and Knaves.
https://www.goodreads.com/book/show/53232141-games-for-your-...