We will stay a couple of nights close to Costco (by Disneyland), and there seem to be few other places to buy drinks and snacks. Do you know if we can shop there without being members? It's our first stop after the airport so if we can't go there we have to do some shopping at the airport.
Costco in Shanghai, including the location near Disneyland, generally requires a membership to shop inside the warehouse. Unlike in some countries where non-members can enter with certain restrictions, in China, entry without a membership is usually not permitted for regular shopping. The staff at the entrance will check membership cards, and non-members are typically not allowed to access the shopping area.
However, there are a few alternatives if you don’t have a membership:
If your first stop is right after arriving at the airport, it is more practical to purchase drinks and snacks at the airport shops or nearby convenience stores before heading to your hotel. This avoids any complications at Costco if you do not hold a membership.
In short, unless you already have a Costco membership or are planning to use the café, it’s unlikely that you can shop inside the warehouse without one. Planning ahead with airport or nearby convenience stores is the safest option for quick supplies.