'What I wish I had known' as a starting DM

Some thoughts I pulled together on a private discord:

1. Recognise what elements of world-building actually give you bang for buck. My first game I have designs for the coins of the realm - relevant? Never came up. I detailed whole towns that the players blasted through, talking to 2 people before heading on. So, while it can be lots of fun to work up your world and that can be fun for you outside of the table, my single greatest learning was doing most work on the things players would likely interact with, have a few contingencies, and then a just a list of names to ad-lib anything else they decided to do

2. Mediocre artists borrow, great artists steal. All your favourite things, wherever they came from? You can use all of those for inspiration. Everything goes in the pot, there is no 'legitimate' source of inspiration. Just repaint it enough not to be immediately obvious and you will probably get away with it

3. Session Zero is your friend or Check what your players enjoy and make sure they get a chance to do that. Both a pre-campaign session and a brief post game 'where do you think you'll go after next session' gives you a heads up on where they are likely to go and what type of thing they want to do - tomb-diving, politics, exploring etc. - and makes sure you are preparing hooks they will probably go for.

Note - there is a lot of fun to be had world building things your players will never see - as long as you are clear that this is you noodling about in your world for your own entertainment and you will not feel too sore if it is never interacted with.

For further reading on the topic here are some blogs of wisdom:
Harbinger Games DM tips.
Sly Flourish DM tips.
Advice for OSR DMs from Goblinpunch.
The Ultimate D&D SESSION 0 Checklist has a lot of distilled wisdom in it.

Should you prefer videos then here is a selection of DMs - give them a watch to see who are your favourites to listen to. In my experience all these people speak the truth, the question is which do you find easiest on your ear.
Running the game with Matt Colville.
What Should You Have in a DM Binder? by Dael Kingsmill.
Building Your Own Campaign Setting with Matt Mercer & Brennan Lee Mulligan.

If what you want are podcasts; check out our friends at The Adventuring Party.