The hell kind of training do you need to operate a self checkout? Make it boop on the products, put em in bags, then either give it the card beeps or cash and get your change. Simple as.

The only thing that gives me trouble is the dumb anti-theft system that sometimes thinks stuff in my right hand is being stolen because I have too many items and no cart, but that's the dumb ass system not me, it literally watches me scan it it just doesn't like where in physical space I was holding it before I scanned it, fix yo' shit.