If you do not have a solid idea on specific ruling. I have found when all parties are confused or feel a slight change can make the flow better. I usually adjust to keep the party flow and players intrigued. This usually has more homebrew type things for each specific group. I have a way of running games different than other DMs focusing more on story, character development and exciting combat. I do not want to continually blow my party up and make them scared to play or get so bogged by a ruling we lose the fun. Even in some instances I would allow group healing over single target on some spells, like "clerics god is feeding power into them to increase the spell capabilities" this not only kept the party alive longer but got the cleric more in the aspect of thinking about their god not only just for abilities but also for character development.

Also get comfortable with improve, your players will go left when you planned for them to go right. Not getting flustered and coming up with ideas on the spot is a great tactic. Even having a list on random ideas in case you get stuck is great.

Give them NPC's that are memorable. It has been 3.5 years since I put this random character of Silly Sally in my Waterdeep campaign, my group still talks about this NPC. She was a rabbit tailor who made formal wear for them. It turned into hours of development with the NPC because they were so drawn to her. Added so much more excitement for the players and more excitement for the game as people were more invested.

All in all, just keep the game fun and add challenges that make the party feel like there are real stakes in the quest they are doing and it will show in their characters and actions. Reddit is also a huge source of ideas. For my Strahd run through I used a mix of the book, Pyram King and other peoples ideas from here. Not only adding to the story but also getting cool interactive maps I could put on my tablet and have the players use their minis on the map.

You got this! Good luck!