I'll give you my opening scenes I used for my latest game. Cover things like combat, skill checks and uses, class specific mechanics, social interactions, and using their creative muscles to solve problems. If you are working with a table of all new, or mostly new, players then it's advisable to make sure the first few sessions cover the basics of how D&D plays. If you're going to do a one-shot, make sure to let your players know if they'll be keeping their characters when they're done or if you'll be doing a whole new cast of characters for the next game(s). Then you get to character generation, this way the players can bounce ideas off each other and you can help guide each other through the process. Then you'll have the players give you that type of information as well, what they want from you as a DM, what kind of settings, themes, or play styles they want to use or have, approach any supplemental material they may want to use, and so forth.

Session 0 is where you take the time to explain what you would like from your players, what type of setting they'll be playing in, the special rules (house rules) that may be in place, your views on pvp, and address any other important information you want your players to have before even rolling up their characters. Monstrous Compendium Vol 3: Minecraft Creatures

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