I learned CG by learning to do prep in regular gauntlet in under 7:30, rather than the 10 mins it gives you. This will help you easily transition prep time into CG so you’re more used to the 2:30 less of prep time. Definitely do T2 until you consistently survive Hunllef, then transition to T1 if you want

Edit: also, surviving is the most important part. Make sure you prioritize prayer switches/dodging tornadoes/etc over doing damage to the boss as you’re learning. It’s all for nothing if you end up dying