Prepare a brief resume, and rehearse, rehearse, rehearse for the job interview. This role-play will be hugely helpful. Even seasoned applicants often break out in a sweat at the thought of having to interview for a job.
First, know what to expect in an interview. Go over probable questions, which will help you formulate your answers. Then, assume the role of the person doing the hiring, and put those questions to the hope-to-be employee.
Note: No matter how old you are, interview role-play is a great tool for preparedness.