What happens next???

I wrote on here a few weeks ago about having first part of alcohol support assessment. Since then I've been seen by a nurse and have been put forward for a medicated detox at home using some benzo type tablet which should be at the end of month. I've had the dreaded convo with my mum as I need someone to stay with or the only other option was hospital detox. Before I do detox I have to attend a pre detox group and I have my first on Monday which I'm really nervous about because I don't really know what it entails, is it a they give us a load of info or are we meant to contribute. I've also got a list of a load of AA meeting and NA meetings but again I'm nervous, all I know of these is what I've seen in shows, you know the standing up in the middle of room saying I'm chemical tap and I'm an alcoholic/addict. Has anyone done these things, is any one able to talk me through what's happens at AA/NA, can I just be quiet in them or do I have to talk from the first one, and the same for pre detox groups. Even detox with librium is it horrid or will I just be out of it on benzos. Because I don't know and its almost like I've done the reaching out and getting support stage becauze i dont know what happens now I feel like my brain is trying to convince me that it's not that bad, me and the professionals are being dramatic, even tho I clearly know neither is as they don't hand out medicated detox to everyone.