The questions will be very much based on your experiences you have described in your CV.
My advice would be to know your CV inside out, think about what is interesting about your experiences, what maybe is missing from your CV or could be stronger, how your experiences have pushed you towards commercial law and the firm you have applied to.
I suspect the question will be much more targeted rather than open questions - “what did you like working in your team at X employer? rather than “tell me about a time you have worked in a team”.