The shopping cart is one of those "grow with you" toys. We have the Little Tikes Shopping Cart.
In Matthew's experience, it was not a good pull-up-to-stand toy because:
1) the handle was too high for Matthew to reach and get a good firm grasp when he was sitting on the floor.
2) it rolls very easily and didn't stay put when Matthew tried using it to pull up. He tried when it was on the linoleum though. Maybe it would've been better if it were on thick carpet.
3) it tipped over (forward) when Matthew pulled up on the front part of the cart.
As a push toy, it worked very well when Matthew could steer and didn't rely on it to hold his weight too much. He started pushing it around successfully when he was almost walking independently. He was 21 months in the above photo and had started taking independent steps at that age.
We tried giving Yuri a ride in it but he didn't like that at all.
I've even toyed with the idea of taking this shopping cart with us on one- or two-item grocery runs and use it for a real-life (as opposed to pretend play only) learning experience that he can associate with his shopping cart. But I decided it was too much work for me. I know he gets the idea of grocery shopping though. While he sits in the cart, he enjoys putting (unbreakable) items into the shopping cart for me. There are several grocery stores that have kid-size shopping carts although none in our area.
As Matthew's language improves and his interest in more elaborate pretend play increases (and when Elizabeth is older, she may force him to play pretend grocery store with her), he'll be "shopping" around the house for items. So if the TV remote or car key goes missing, it'll probably be in the cart, right?