店内 (tennai) means “inside the store” | MotiTan Japanese Dictionary

More examples

混雑時は店内でお待ちください。kon zatsu ji wa ten nai de o ma chi ku da sa i

Please wait inside the store when it is crowded.

Marks the space within a store where people shop, eat, or carry out other activities.

店頭tentō: The area at or near the front of a store, where goods or services are presented to customers.

店の建物や敷地の内側。mise no tate mono ya shiki chi no uchi gawa

店 (ten, "shop") + 内 (nai, "inside") forms a Sino-Japanese compound for the inside of a shop.

In Japanese retail and restaurant language, 店内 (tennai) often appears on signs to mark what happens inside the premises, where English often uses a phrase such as "dine-in" rather than a single noun.