Today I tried my first meetup in Zwift. Here is a how-to from Zwift Insider if you want to try it out too. A couple of things I learned, if your friends are late even 1 second after start time, they will miss the ride. Also, I did our ride on a route that I had not yet gotten a badge for to see if I could do the ride and get credit for the route. The answer there is no. The route you choose on the meetup, you will not get a badge for. For visual learners here is a great how-to from the Lama: