Here's what I had to do in regards to the physical: Height and weight, EKG, vitals, head to toe exam, general ROM (no duck walk), a legit hearing test (the one in the booth), visual test, blood work (electrolytes, CBC, cholesterol, BG, HIV, etc), and a dental exam. They'll look for anything that is abnormal....ANYTHING. If it's abnormal you have may have to go back and have it evaluated and possible get a waiver. I had two knee surgeries while I was on active duty as an enlisted person and I had to get that scrutinized (even though they already said it was fine while I was still in the military the first time!). That took about a month.
As for the interview, it was pretty casual. I interviewed with two retired Captains (O-6). They asked me why I wanted to be a Navy Nurse Corps officer, if I knew what to expect in the military and could I handle the possibility of getting deployed (love being deployed), where do I see myself in 5 years as a NC officer, how I was doing in nursing school (including my GPA)......and....that's all I remember. It was probably the easiest part of the whole application process to be honest. Mainly because I'm prior service.
Just present yourself professionally. Sit up straight, be polite and respectful, speak like you have a college education.....you know, the typical interview protocol. Oh yeah, do a bit of research about the Nurse Corps and the military before you go....it may not look that great if you have no idea what a NC officer or service member does in the military. And don't make it sound like you are just joining for the benefits. I'm not saying that is why you are joining, but some people may mention how much they enjoy the benefits provided to service members (BAH, travel, free schooling, medical/dental coverage, etc.). It's fine to mention some of that; it's to be expected. But definitely work into the interview what YOU can provide the military.