Q. What is it supposed to be on the show? A. A store that sells equipment for hunting and fishing, such as guns, knives, apparel, etc. Q. Where is it supposed to be on the show? A. In Iron Lake, New York. Q. When did we see it on the show? A. In Episode 1, of Season 9, "Cold Snap". This is where Dexter works behind the counter at a sales associate, under the alias of Jim Lindsay. We see Dexter arrive at the store in the morning, with a pink box of pastries, and open up the business. The shop is owned by Fred Jr., a genial guy who is the partner of Pastor Brian. This is where Dexter encounters Matt Caldwell, the obnoxious, rich son of the town VIP, Kurt Caldwell. Matt comes Into the shop and asks to buy a $9,000 rifle, and tries to persuade Dexter/Jim to sell him the rifle without doing The required FBI background check. Dex refuses to bend the rules for Matt. Q. What is it actually in real life? A. The Bridge Street Bazaar. Q. Where can I find it in real life?

A. The Bridge Street Bazaar can be found at 6 Bridge Street, in Shelburne Falls, Massachusetts.

It is located right next to the iron bridge, on the north side of Bridge Street, at the east end of the bridge, in Shelburne.

In real life, it is sort of the antithesis of a hunting store, a shop that seems to have more in common with Woodstock than with Smith & Wesson.

The store describes itself as a "Bohemian Lifestyle Boutique", selling unique clothing, jewelry, shoes, and accessories. And it does indeed seem to have an esoteric mix of items for sale, leaning towards the countercultural, such as silver Celtic knot pendants, carved owl earrings, fake ear gauges,and "Adaptogenic Immortality Powder".

You can find the store's website here: https://bridgestreetbazaar.com .

For the show, they completely changed the window displays and the inventory, of course, to make it look like a hunting store, complete with mounted animal heads on the walls. and they added a red, oval sign over the front door reading "Fred's Fish & Game", and featuring a flying duck.

And they completely remodeled the store's interior as well, right down to adding stuffed animal heads on the walls. The resulting rustic ambience was so authentic that customers actually came in  expecting to buy fish & game equipment from the store. ( Note that you can see the town's Iron Bridge through the store's front window during interior scenes. )

Here is a Google StreetView of the shop:
(pan to the left to see the iron bridge)