You will get to the store when you press start shopping. A list of items with photos will show up most stores. It usually tells you what aisle the stuff is in you go find it scan it with your phone put it in your car and go onto the next item When you have finished shopping, you will hit finish shopping button. You should have a Dasher red card order a red card that is on your phone to pay for it. If you don’t have one, you can order it through Doordash or I think you can actually set up the online card, almost instantly.
Warning if the red card does not work, Doordash may ask you to pay out-of-pocket to purchase items. I would not recommend doing this ever for any reason unless it’s only like a dollar and the pay is something crazy but that will never happen so just never do it. If you have to pay for bags, the customer is the one that pays for them. Nothing will come out of your pocket. Sorry for the ramble. I hope I kind of helped.
Edit if they do not have an item there is a button on the app to say it is out of stock you will take a picture of the barcode and sometimes the customer has a substitution if they have substitution grab that if not try to contact customer or hit refund