I tried the "just show up early" advice and got locked in a storage closet
My first job was at a grocery store in Phoenix and I got there 30 minutes early my second week to look good. Manager forgot to tell me the back door auto-locks from the outside, so I spent 45 minutes in a 40-degree freezer room before someone heard me banging. Learned to always carry my phone and never trust "just wait by the loading dock."