I'm not saying don't get a face shield, but even with shield and mask you still want to maintain distance.

Last time I shopped in a grocery store, I went when it wasn't crowded and prioritized staying away from people. If someone came towards me I went the other way. If someone was already in an aisle pointed toward me, or was pointed the other way but not far along, I didn't go into that aisle just then. If someone stood in front of an item I wanted, I came back for it, or skipped it if it wasn't important.

I also wore a mask, but I treated that store as hostile territory, focused on avoiding people, and got the heck out as fast as I could.