First, she thought that this is Betrayal, but then she thought he’s right and they have to start acting kind of like enemies, because the Hunger Games will start soon.
2. What is Effie working with Katniss on? Haymitch?
They both prepare Katniss for the interviews. Effie is teaching Katniss how to walk with manners and be like a woman on high heels and with a dress. Haymitch wants to practice with her on how she should present herself in the interviews, so he has to get to know her.
3. What is the point of the interview? Why is Katniss having so much trouble with it?
The point of the interview is depending on how Katniss presents herself in the interview, she would get more or less sponsors.