The most important skill for an account manager to have is attention to detail. The second most important is patience and an ability to work with all different types of personalities. I would prep for the interview by brainstorming times you worked on a project and managed many different assets or people. Try to come up with examples of when you were juggling multiple deadlines and demands. School work is an okay example, just do your best to make it more about the skills your learned and not the specific project you were working on.