Glad to know that you got the opportunity, but most if it depends on how you got it. Being a fresher, I am assuming, you got it through your famous uncles and aunties working for the biglaw (pls, don't take offense) and if it is really the case, then a general know-how of the area you are interested to work in along with a basic introductory speech would suffice. Also, take note of the recent developments in the area.

If not, then get ready. Be consistent in telling your story - your internships, your publications, your achievements, your experiences and your takeaways from them. Get ready to demonstrate the things that you have mentioned in your CV, whether it is how effectively you have managed the work assigned to you at your internship or the crap bundle of skills that is their just for the sake of it. Keep the contents of your CV relevant and aligned to the position you have applied for. Participate in the process, provide your inputs and discuss things.

Lastly, have the knowledge threshold. Be thorough, especially in the area you are interested in. Put your pricey law school education to test.

Be confident and you will be through. Keep up the attitude, be friendly and don't be bothered by the questions. No one can answer all the questions, but your response to them can make all the difference.

All the best!