It never hurts to attend AA or NA meetings when you have a pending charge for several reasons. First, if you decide to take a plea, it shows the prosecutor and the judge that you are aware of a potential problem and have already taken steps toward rehabilitation. Judges and prosecutors usually help those who help themselves first. Your chances of a better deal are greater if you can prove you've been attending AA. Second, you may actually learn something at these meetings. If anything, it will show you if you really have a drinking problem. There are several different types of AA meetings, you are sure to learn something. Third, you have nothing to lose and everything to gain by attending. The meetings are free, anonymous, and located everywhere at just about any given hour of the day. Whatever you say in these meetings is inadmissible in court.
Just be sure to have the meeting moderator initial on a log sheet (can be a piece of notebook paper) that you attended the meeting. If you decide to take a plea, or if you take it to trial and get convicted, you've got some good mitigating evidence in sentencing. If you get an acquittal, then all you've lost is a little bit of time, and hopefully, you've gained some insight about alcoholism.
Hope this helps.