You might be slightly confused this week by the fact that you don’t know who wrote each message. That makes it slightly trickier to guess at cribs, and also to to use what you know about the protagonsists to guess at the type of cipher being used.
That is deliberate of course, we don’t want to make it too easy, and you can work it out! The frequency calculator is usually pretty good at suggesting whether a cipher is using a substitution (when the frequencies look suitably similar to standard English, but jumbled up), or a transposition, when the frequencies look pretty much exactly like plain text should look, with E, T and S very common and letters like Q much less common. That together with your skills in these types of cipher should be enough to get you started.
Of course, there are other ciphers! Polyalphabetic ciphers completely change the game, as do those that subsitute pairs of letters rather than individuals, but we are not cruel enough to use those (yet!).
Keep plugging away, you will get there!
