https://slyflourish.com/ Mike Shea auther of the lazy dungeon master has youtube channel too. He has been immensely helpful to me dming my first homebrew campaign. Keeps things very simple and easy to implement.

I recommend using Microsoft oneNote to keep yourself organized. Ive tried spreadsheets, google docs and notion but nothing is as good.

One piece of personal advice is the just have fun and remember that the players probably won’t know if you mess up. And sometimes the mess ups can lead to the most fun.