What should I expect from a law firm open day?

I’m going to a law firm open day next week and am a little bit nervous about it since it will be the first time I will have ventured into a City law firm’s offices.

I’m going to a law firm open day next week and am a little bit nervous about it since it will be the first time I will have ventured into a City law firm’s offices. What shall I expect – I’m particularly worried about the group exercise.