Its the military. There isn't much of an interview, other than if you are able to join. Verify minimum physical fitness, education, and drug test. Seek available jobs to suit your needs.
I applied in-person. I interviewed at US Marine Corps (Atlanta, GA) in Jan 2016
Interview
Upfront and personal. They ask you questions and you answer them, they will ask about drugs a thousand times and possibly in a thousand different ways. Don't try to flatter them or try to be a cool guy, it's only going to make you an office joke the second you walk out that door.
I applied in-person. The process took 2 months. I interviewed at US Marine Corps (Plant City, FL) in Jan 2019
Interview
Talk to recruiter in your local area. Go to MEPs and pass all physical examinations. Prepare yourself mentally and physically. There are many job choice to choose from when joining the USMC. Your job choice is not guaranteed.