How do group rides work

How do group rides work? How do you know which routes their taking? Are they custom routes?

Most (all?) group rides follow standard routes that you can select from the start screen. e.g. Road to Sky, Hilly Loop etc.

If you’re doing an organised group ride event, you’ll automatically go the right way. I can’t even recall whether the turn signals come up, but even if they do you can’t choose to go the wrong way.

Just join the event, and when the event starts pedal until the finishing board comes up. =)

Look in the Companion app.

Thank you!

Hope this information helps.
You can look for group rides on the Zwift events page but to find more details (like route) you have to go to the companion app (I use the android app on an android phone).
For instance, The HERD Mellow Monday, listed on Zwift Events for 5:15 pm CST on Monday. You can see the time, duration, w/kg target and instructions as well as some links to the organization’s information pages.
IF you look at the same event The HERD Mellow Monday on the Zwift companion app you can see, Route - Jungle Circuit, Number of riders who have signed up (194 at this time) as well as the number of people YOU follow who have joined the ride.
An internet search for Jungle Circuit will bring up a page for zwiftinsider as well as zwift. Either will give you details on the route, distance and elevation.
Once you start a group ride you will automatically follow the route unless you leave the event or quit the game.
Have a great day.