You bag your own. Generally the cashier puts the scanned items in an empty cart sitting there for that purpose, then you swap your empty cart for the one with y

You bag your own. Generally the cashier puts the scanned items in an empty cart sitting there for that purpose, then you swap your empty cart for the one with your purchases in it and wheel it over to a counter against the wall to bag or box them up - at the counter there is a stockpile of empty boxes that you can take.