Hello, if it is a large-scale unified management law firm, it may issue work clothes, usually suits. If you don't, you'd better wear a formal suit to work, not too formal, as long as it's not too casual. If it's a business job, it's best to wear professional clothes to give the impression of customers' professionals. If it is the work of an internal clerk, it should be leisure. These are not difficult to judge for a smart person, and can be seen from the company atmosphere.