Read the forum during the day leading up to the ride and someone will say who will start the ride. At 7 o'clock UK time the starter will open up the session and there will be a 10 minutes warm-up. That gives you 10 minutes to find the correct ride and log on

Warm up with the others until the timer starts to cont down - probably best to stop pedalling about 30 seconds before the start as pedalling once the clock has gone to zero will leave you standing on the start line! At zero, step on the pedals and pedal like you stole it

Don't stop until you get to the end

If possible, try to find someone at the same pace as you and draft behind them - make them work all through the race then jump past them with 100 metres to go
Good luck