These resources can be used to help you understand how to get a job shadow, prepare for a job shadow, and be respectful of a business / employee who is hosting you.
A job shadow involves spending time with an employee at their worksite to observe daily tasks, interactions, and learn more about the workplace. In the job shadow, you will have opportunities to ask questions and may also have the opportunity to help out in some tangible way. This sort of experience can lead to invaluable insights. Additionally, it is a great way to start developing a professional network in a career area of interest.
This one-page sheet provides a succinct overview of what a job shadow is.