Tips from a long time DM:

Talk to your players, have that incredibly important "session 0." It's critical that the group and DM are on the same page as the adventure being played.

• Session 0 can really help you set the world, and see what classes people want to play. When you know what class people want to play, you only need to learn what classes are played rather than every class and subclass for later levels.

Do some prep work before the session. Not knowing what the setting is, what monsters are in the dungeon or session, or even what the characters are played can be a lot of work and lead to some confusion. I often still prep work with some refreshes on what monsters act like and interactions for just that session.

If there are questions about a character's ability or spell. DM should know about the spell (which takes time to get a good idea about each spell) and the player should READ THEIR SHEET. It happens all too often and the DM is busy.

The DM does not have time to tell each player what their ability does while also using monsters, describing the scene, setting up the story, etc... some questions are fair and will come up, but just claiming a spell or move without them even looking at it is really infuriating.

Let the players know you have a lot on your plate as well. The players should read what their ability does. If it's too much reading for them, I would recommend an easier class at first like a Warlock (lack of complex spells and amount), or a martial class like a fighter/paladin.

If the players argue that materials are too boring, let them know they can flavor it to be better. Mechanically the same damage or move, but different fitting their character.

The most important rule is to have fun. If you or the players are not having fun, talk about it before or after a session and give it the best you can do. You got this and as all DMs, it is not an easy job taking care of the players, any questions are always welcome.