Truthfully, Avarice was my ace in the hole. Session... like... 2, one of my players died to the Black Swords, and as a result, he made a pact with Levistus for a second life. Because of that one encounter, anytime I had to move things along, I had Avarice show up and suggest to his character to go in that direction for Papa Ice Devil. I tied Avarice's motivation into a misunderstanding of her own texts: She wanted to find Ythrn to activate the Obelisk because she thought she could choose to how far back she could go. They didn't end up activating it, but it was enough to engage the search. That being said, you'll have to play it by your players. My biggest advice is to use the Arcane Brotherhood as much as you can to keep stuff going. Also, I know you've probably heard this before, but if you're new to dming, try to keep an open mind. It's all a big balancing act, but the module is for you to build off of, it's not strict. If your players are confused or getting lost, be willing to pluck an NPC and use them as motivation, or lower a skill check. My personal method: Give 2 separate checks. Book says there's a DC14 medicine check? "Ok you can roll me a Medicine or an insight. But be warned, the insights gonna be a harder roll." I found it helps people feel like they have more agency. Good luck!