Will Ideal Buy, CVS, or Walgreens accept volunteers?

Most for-profit companies/organizations will not. Allowing “volunteers” opens an entire can of worms in terms of legal issues. As a “volunteer” you wouldn't be covered under any type of workers compensation, insurance, or employment regulations. I’ve first hand experience with a similar issue involving interns. For my company we hire unpaid interns but they MUST be receiving academic credit from their college or university. This is because the credit would constitute their work as for academic purposes. If they were not receiving academic credit then they would be “volunteers” and not covered legally. If you’re looking to get your foot in the door without pay look into any internship programs these companies might have in place.