Criminal damage

[ccfccasual]

I went to a football away game in london and i had a few drinks and after the match i was arrested for criminal damage (i punched a wing mirror of a car). I have been released on bail and am due back at that local police station next month. It is my 1st ever offence and i have never been in trouble with the police before. I was just wondering what is likely to happen to me?

Many thanks