The job was extremely stressful, as I had to manage a large variety of different tasks at once while feeling like the managers were figuratively breathing down my neck, which was quite overwhelming for me. (For reference, I have autism, and I get overwhelmed very easily.)
The store was quite understaffed near the end of my time working there, making the job even more stressful for me. This was nobody's fault, as I could tell that the job was taking its toll on others as well, managers included.
I felt that I was not adequately trained, as my training was rushed quite significantly, in order for me to get me on the shop floor as quickly as possible. This caused a lot of gaps in my knowledge.