Can I work at a Japanese restaurant and practice my Japanese?

Of course. The most important thing in learning a language is to have an environment, to be familiar with the context, the way of speaking, and the tone of a certain language.

But you said it, it's going to a Japanese restaurant. The people around me are talking about things that are more or less related to the content of the restaurant, which means that the content of learning and exercising is very limited.

Japanese restaurant in China?

I don't think it's useful, the service staff will do some daily [.]

Even if there are Japanese guests, you are not allowed to chat with them.

If you work part-time at a restaurant in Japan, that's a different story.

I've been to a Japanese restaurant, and I personally think it depends on whether the Japanese restaurant you go to depends on whether the staff you can get in touch with are Japanese, or whether the customer is Japanese or not.

You will learn a lot about the names of Japanese dishes, but you won't have that many opportunities to actually talk to customers.