As stated by previous posters, if you want to be a nurse in the OR, first you have to become a nurse. If your question is getting more toward how to get a job in the OR once you are a nurse, the best way to do that is to work in the OR in nursing school
. You can work in housekeeping or as a patient care tech. (Working as a scrub tech requires training beyond just getting accepted for the job, and if your real aim is to be a nurse, your time is best used focusing your education time on nursing.)
I try so hard to make people understand, the best way to get a job is through networking. Anything you can do to meet and make a positive impression on someone in a position to help you get the job you want is gold. Even if you were just volunteering in the OR (our OR doesn't use volunteers, but some do), that's something. It's experience, and it gives you a chance to meet people who can help you out. It's all about relationships.