If you guys are relatively new riders then I would recommend to keep the group size not more than 5 (better 4) riders. I'm a relatively new rider too and speaking from my experience with previous group rides.
Also, because most likely it would be the first time when you meet/ride together and no one knows each other riding skills/style, I would recommend doing "organized ride". I.e. a classical and safe ride when everyone follows rules..
In addition, it would be helpful if people who never participated in group rides read/watch videos about group ride rules/tips. Just basic things, like what a leader should do, hand signs, hwy riding/lane change, what sweeper does, etc. Ideally, the leader and sweeper should be more or less experienced (in group rides) riders. And it really helps if the sweeper in wears high vis gear/helmet. Better keep it safe than be sorry.
If you guys plan to meet at some point on weekdays then I would drop in and say hi (weekends mostly occupied with family stuff).
@Evoex, do you know if Kawi/2nd Cup Wednesdays are happening this year? I didn't check it this year..