I often find that most groups on a professional meeting don't stand too close together and if you step in a bit, those around you will move to incorporate you p

I often find that most groups on a professional meeting don't stand too close together and if you step in a bit, those around you will move to incorporate you physically in their circle and, as a result, in their conversation even you haven't said anything not anyone said something to you. You can listen a bit, if you like the conversation you can join, if you don't there's no harm in stepping out again. Even if you don't know what to say, or you're shy, by physically becoming part of a circle, you've entered the conversation. There's no awkwardness. Now, in you would try that in a close-knit group, you'd be seen as an intruder, imposter, or potentially danger (to the alpha of the group). Don't do that.