Hello Hunji. To directly answer, "What's your store?" can not mean "What's your name?".
I partially agree with Mag's response, but it WOULD be common to ask 'What's your store?' in an introduction, if you are at a trade show, or a watching e-commerce videos. Example: "Hi, I'm Jonathan, I run a sporting retail outlet... what's your store?" - in that context would be asking what specific area of a sales market someone is participating in.