2nd Interview for mental health RN

Hello! I interviewed for an RN position last week in a mental health unit, and I just got a call for a second interview for tomorrow! I'm a new grad, so I'm very excited and nervous The unit is 90 beds (30 men/30 women/30 kids) and has an open unit and locked unit on each of the 3 floors. I would float between the open and locked unit, and although I'd be assigned to women, I'd also float floors. Psych has always interested me, and I know I'll enjoy doing it.

My question is this: My career goal has always been ED nursing. I understand, as a new grad, getting into the ED (espcially where I live) is tough, so I'm VERY open to starting in another unit to get some experience and "get my foot in the door" so to speak. Do you think I will have trouble transferring from mental health to the ED or a med floor?

I'm just looking for some advice - I know it's up to me and what my heart tells me, but I like to see all sides of things when possible!

Thanks!!