J.M.
I am remembering now that awkward time. Too big for the infant seat, too small to sit on their own, too heavy for baby carrier...
I spent several months using my stroller as the shopping cart. It has a big storage space on the bottom. I always worried that people would think I was shoplifting, but that never happened. I would even use it in the grocery store for a quick shop to pick up a few items. I suppose one could use two carts. One for baby to lie in on a blanket, the other for food...
I liked the idea of online shopping. I haven't tried that for groceries, but I do use Schwann's. Great quality and selection.
A couple of stores had carts with infant seats attached. I personally found the straps to usually be broken and how clean could it really be?
Good luck!