>>274193557
You need to know who your friends are within the larger group. You can make friends with other people who aren't on consistently, but then they're not on the next time you are. To the people who are the backbone of the meetup, the ones there every single day for at least a couple of hours, you need to make the same commitment if you want to get to know them on the same level they know each other.
Those people are a minority, though, and if you can organize a consistent sub-group around an event like >>274193330 suggests, then that can work around your own schedule.