I have a ford mustang mustang V6 its shaking i went to auto zone they said i need turn up but i did turn up?

I have a ford mustang V6 its shaking i went to auto zone get a test they said i need turn up but i did turn up less a month ago please

Turn up what. Radio

What makes you think that the clerks at auto zone know anything about cars except how to look up parts on a computer?

I don't know they told me the code said tuned up and I did tuned up last month but still shaking please help