Dehillerin is hard to beat. They have the classic molds, copper pots, wonderful knives etc. They are basically a restaurant supply place. We have some very cheap steak knives with little bees on the back that work just fine -- they cost about 2.50 and work as well as those with hand carved wood handles that cost 20 times that. We also have several expensive kitchen knives that are terrific. For years we rented random apartments and invariably they had terrible knives, so we would buy a good knife at Dehillerin and use it and take it home. We have half a dozen wonderful mismatched knives in our kitchen and love using them. There are a number of other stores in the general area; we bought opinel type folding knives last time we wandered the area in one of them but don't remember the name.
Here is what I came up when I googled:
https://www.thekitchn.com/best-places-to-buy-kitchenware-paris-254957
I will try a couple on our next trip.
Some Wpeople recommend BHV but in my experience they have the exact same stuff you can buy in the US in any department store cookware department but it costs much more due to VAT.