To browse and join groups:
Tap on the chat icon at the bottom of the screen
Tap on “Explore”
Scroll available groups and filter them by mode, days and destination or simply search for a group by clicking on the filter in the top right corner.
Switch between map and list view, if you want.
Tap on a group
Tap on “Join group”
Tap on the question mark on the map to get detailed explanations about what it displays.