I have a question regarding about the Security Clearance at a Air Force in US. I have phone interview next Monday and I do not possess a security clearance. I am wondering if I am supposed to have one before getting hired. What is the process and what are the requirements?

The job for which I am interviewing is in another state and where I live there is a military installation nearby, about 30 miles from my home.

If I get an offer and need to do the security clearance, can I go to the bar near my home and apply for the security clearance there?