An affray is the fighting of two or more persons to the terror of Her Majesty's subjects.
My guess is that you have not yet been charged with the offence, since all the evidence will have to be assessed by the Crown Prosecution Service, who will decide if there is sufficient evidence to bring the appropriate charge of Affray against you and other persons involved. If that is proved to be the case then the trial will be before a Judge and Jury at the Crown Court and the Judge will decide on the appropriate sentence, which, in most cases amounts to two years' imprisonment. The offence of Affray is extremely serious.