Hi
@Joffey - welcome! Obviously Zwift has loads of organised events (races, workouts, non-competitive group rides) which you can join via the companion app, but in addition to those, we like to organise our own races and keep track of results in a monthly league - basically because it's good to race with people who you've got to know rather than just random people on the internet! There's some really close battles between people of similar pace throughout our little league.
We normally race on Tuesday's at 6pm (UK time) and Thursday's at 7pm - you can join one or both. However, this month we're going to do the Tour De Zwift stages (starts on Jan 12th) and use the results from Zwiftpower for our league table. When Tour De Zwift is over we'll probably organise our own league races again which we do via the meetup function.
So if you want to join in with our league you're welcome to, but you'll need to be signed up to Zwiftpower if you're not already (you'll also need to be on Strava for our the races we organise ourselves as this is where we get stage times from).
Any questions, just ask