Working different types of jobs means working with many types of people. Not everyone you meet will have the same background or the same experience as you. However, coworkers are just as essential as the job itself. You will most likely learn just as much from the people you work with as you will from training or the job itself.
I remember working my first summer job after my freshman year in college. My work experience started much later than most people around my age. At that point, most probably started working at the age of 16 or 17. It was a typical minimum wage retail job.
I learned a lot from customer service to store appearance. While most was through on-the-job training, I also learned a lot from my coworkers. It was so much as one person, but most of the people that worked there. A few had had jobs similar to this one in the past and had been working this job for a while.
Since they had longer pasts of part-time jobs, they were able to guide me and give me more insight into the world of part-time retail jobs than I could have learned on my own. Sure, I could have caught on eventually. However, I would like to think that their advice and guidance helped me to learn faster than I could have alone.