Personally, I'd recommend the Beginner's Meeting - you're more likely to find people who are starting off just like you and the topic will more likely be about taking the first step, realizing there's a problem, making a decision to get sober, etc....... In a discussion meeting it could be about anything (tackling resentments, loneliness, whatever).
No one is going to ask you to give a speech (!)... a lot of people don't say much they're first meeting other than why they're there (drinking is a problem and they want to get sober). Everyone is scared at first and believe me, they understand because they remember being there!