Who qualifies to apply for instructor positions or assistant professor positions?

I am a math PhD student in my last year, and I've been on mathjobs.org looking for jobs.

I see a lot of jobs for instructor positions, or jobs titled "assistant professor", where the main work load seems to be teaching undergraduates and no research.

It seems that the main qualifications are a PhD. I am confused on what kind of applicant is qualified to apply. It seems that I am qualified enough to apply, assuming I receive my PhD by the time the job starts, but I am worried I am being naive. I do realize that someone that has already had an instructing position, or "assistant professor" position previously, or experience as a postdoc, would look better than a fresh PhD.

Are these jobs typically given to PhD's that have been through a few postdocs, or do PhDs straight out of grad school have a fair enough chance at getting the job?

To be blunt, am I wasting my time applying for these positions?