The bset way to prepare for your Interview is to bring a lot of evidence, especially evidence to support your relationship. Good evidence is bank statements that show joint accounts insurance papers that show both your names on them like renters insurance or car insurance. If your rent you should bring all your leases that prove that you and your husband live together. Bring any statements from banks that prove that you have joint loans like car loans.
My interview was over in 5 minutes. The officer only asked how we meet, and why we waited so long to get married. Other than these questions he only wanted to see some eivdence that our marriage was real and that was it.
If you got married for real that the interview will be fine.