I have a interview with HP NMCI. Just looking for advice/tips.

Apologies for the late reply. I just was to thank everyone for the amazing advice. I did awesome in my interview and will be moving on to phase 2 of the hiring process.

1) Know yourself.
2) Know the company.
3) Know the position (job posting).
4) Have an updated & TAILORED resume (several copies as SMSgt Minister Gerald A. Thomas said)
5) Be able to place yourself in the Company, or in the Position.

When you go in, be confident, but remember that "military confident" and "civilian confident" are two different levels. You don't want to come off as arrogant.

There's an old adage, "If you can get the interview, you can get the job." The interview is to see if they can work with you. To see if you are a good fit. They've already reviewed your qualifications (and everyone else), and determined who isn't qualified, so RELAX, really relax and have a conversation with your interview or panel, and explain why you're the best fit.

A phrase I use, that has served me well is:

"I'm a professional, and I like to work with professional organizations."

I generally use this in response to "Why our company?" It shows that I've done my research, and I respect the company.

Security+ is a good start, as long as InfoSec is your desired discipline in IT. I suggest you also start working towards some networking knowledge, go for a CCNA. Look in to the CISSP, it will take a few years to be prepared for it but start working towards the requirements now.

Another good avenue to look in to is some server side training, that will help your security focus overall.