At mine there's one person from the org leading the group and they just ask the group to introduce themselves before asking a few silly questions. After that they asked us questions like "What's something positive that happened to you recently", "what's something exciting that you did recently", "Has anyone had a positive experience with a family member when coming out?", things like that. Just topics that'll start a bit of discussion and socializing. People can ask follow up questions to anyone who answers or give out friendly advice if the person answering is open to it.
It's just a nice atmosphere for trans people to be openly trans and socialize with people like ourselves.
Almost like a curated version of our megathread i guess.
Good luck!! In my experience people were super friendly and non-judgemental. Personally I only introduced myself and then was too anxious to say anything other than whispers to the 2 people I already knew there.