Meetings are Like Dungeons and Dragons
Early in my career, I didn't know how to act in big corporate meetings. It felt like a brand new language that I could not understand. Over time, I got acclimated (sometimes too much where I'd be out and about using corporate terms).
One thing I tell people new to the world is to treat meetings like a big game of Dungeons and Dragons. It will be the most boring scenario you ever role-play, but pretend. This lets you act more confident and able to take control if it does not naturally come to you