Hi Renarde.
Every AA meeting is slightly different in the way it is run so it isn't possible for anyone to tell you exactly what will happen. A closed meeting means that it is only for people with a desire to stop drinking. Anyone can go to an open one..family or friends etc who are there to support.
At some meetings I've been to, we go round the room introducing yourselves and saying we are an alcoholic. At some meetings we don't.
There is no expectation put on you to share or do anything uncomfortable. I would however make a point of telling someone, preferably before the meeting, that you are a newcomer. They will then make a point of looking out for you and you will be given people's numbers to call if you need to. Please do that. They are there to help and it helps them with their sobriety too.
I hope it goes well. Come back and tell us all about it x