In addition to the traditional shopping streets, or SHOTEN-GAI (商店街), there are many other stores and retailers in Yokosuka City.
The largest shopping mall in the area is conveniently located only a few-minutes-walk from the front gate of the Navy Base, and is named: "Coaska Bayside Stores", but often is just called: Coaska.
The mall was built back in 1991, on a waterfront site which had been used by the Japanese Imperial Navy from 1908 to 1945. Originally, located on the site was a huge gantry crane facility for ship construction and launching, which was a well-known landmark in Yokosuka. The crane was dismantled in 1975, and by the late-1980s, a plan was approved to build a six-story shopping center, which would be run by Daiei corporation (a national retailer.) The company currently managing Coaska did a major renovation to the mall from 2019~2020, but the main structure has basically remained unchanged.
Coaska is filled with all kinds of stores, including a large supermarket and other businesses selling fresh seafood, fruits, and vegetables. It has a multiplex movie theater, clothing and furniture stores, a large food court, Starbucks and Tully's coffee shops, a section filled with Japanese and Western-style sit-down restaurants, and much more. Coaska also has lots of parking, both on the ground level and up above on the 5th and 6th floors.
The parking lot has an ingenious control system where, as you enter, a camera takes a photo of your car's license plate, and when you leave, you type your license plate number into a validation & payment machine.
Coaska is a very user-friendly and well-designed mall, filled with all kinds of local goods and products which you may have never seen before, and therefore it would be a great place for your first Japanese shopping and foodie adventures.