Here we've compiled almost everything you need to run your first game.* Minus the players.
Our Starter Adventure is meant to work as a one-shot for new players and inexperienced DMs. We take a deep-dive on how to DM in order to give you a better idea of how to run your first game. The adventure assumes that your players are bringing pre-made characters, like the ones we've generated below, and does not go into any details on character creation.
If your players want to make their own characters, you may need to run a Session 0.
*While the basic rules for D&D are available for free through Wizard's of the Coast, we recommend that the DM, if they already know they're committed to playing the game for the long haul, purchase a Player's Handbook. Alternatively, there is also a D&D Starter Set that includes the basic rules, a starter adventure, and pre-generated characters that can get you started playing for just around $20.