2
First time DM with no playing experience
(ttrpg.network)
A place where Game Masters, Dungeon Masters, Storytellers, Narrators, Referees (and etc) can gather and ask questions. Uncertain of where to take the story? Want to spice up your big baddie? Encounters? That player? Ask away!
And if you have questions about becoming a Game Master you are most welcome with those as well!
Rules
This is a fantastic article on running a session and player engagement, and it's well written: https://www.cracked.com/blog/harmonquests-dm-explains-how-every-dungeon-master-messes-up
I'd also recommend this series the Angry GM is working on, and most of his articles in general: https://theangrygm.com/true-game-mastery/
Both of these guys have run games professionally and give really good, practical advice.