https://docs.google.com/spreadsheets/d/14yZKxht6igwJPXPU0EehKmmN2hx1g3EchEuB5G0yNO4/edit#gid=0
If you click on the bottom tab named Interview Questions, you will be able to see the typical questions that they will ask.
I'm not sure how different the questions from the embassy will be compared to USCIS but my feeling is that the questions will be very similar.
I did my green card interview (EB2-NIW) in the USCIS office in Boston and I thought it was a big waste of time.
They asked me about my job and I had to explain what kind of research that I was doing (I'm a scientist).
After that, they literally ask me questions that were on my application like "1- If I was part of an organization that wanted to harm to the US government or 2- if I was part of a terrorist organization or 3- if I was in a polygamist relationship".
Just be honest and the interview process should be fairly straight forward.