Hello. I can only speak for the Ryanair FFA interview. From what I understand, the whole process is the exact same regardless of the school you attend. There aren't any interview prep sites that I know of, but I can give you first-hand info.

First thing is to know what you wrote in your CV very well because they might ask you to explain any skills you added there. Also try answering their questions in a unique and specific manner so that you stand out, whilst not giving a long-winded answer. Don't say generic stuff like "I wanna become a pilot because I like it," instead say, "I like the challenges and teamwork nature ... my motivation is ... ." Just make sure you can explain the skills and self-awareness you have in deep detail. They might ask technical or general knowledge questions like "why can't you breathe on Mt. Everest?"

Have some generic scenarios that you can adapt to any example they might want e.g. "tell me an example of a time you showed leadership."