Describe the answer of the following Problem

Problem- So after the long wait, when someone finally gets that phone call for an interview at an airline.

Part 1- What do they need to study?

Part 2- What kinds of questions will they ask during the interview?

Part 3- How many interviews do they typically have to go through before a hire decision is made? In short, how does it work?

I want experts help to simplify the answer of the above problem.