What do you folks generally include in your session 0? Do you just go over creation and rules? Do you go beyond that and start chapter 1 of the campaign? What do you do for players that have never played before?

I guess rules and character creation is good to start with.

And then maybe do a mock fight with some goblins or such, just to get them started throwing some dice and understand what the numbers mean.

And to elaborate some more.

Keep it simple, but give them option.

Like:

DM- You see a goblin hunkering down behind a boulder ready to shoot you with his bow. What do you do?

Green player- I run forward brandishing my sword and jump over the boulder and strike him hard.

DM- Jumping over that boulder is hard and daring. So roll the dice for Acrobatics and see if you jump an clear the boulder or miss-step and slam into the boulder.

Green player- Nice. Where do i find Acrobatics? ;)

Session 0 is an opportunity to lay down expectations (e.g. fun > rules lawyering), social etiquette (e.g. behave like adults), group rules (e.g. no evil characters), house rules and allowed content, campaign rules (e.g. meat-grinder mode). It’s also an opportunity to do character creation together and supervised, and for everyone in the group to begin getting to know one another if they don’t already.

In my session 0, especially with a new group, I like to get the numbers done early and then do backgrounds and where each character is in their life. This gives me the opportunity to get a starting point idea of what the Player has in their mind for their creation. With new people, it also gives me an idea of how much game knowledge they have, including the world (if not homebrew), novels they have read (the player honestly wants to play a half-drow ranger whose mother was called Zibrija?), classes (no, I am not allowing the sub-kit “nuclear juggernaut” or your four-meter-tall Warforged oathbreaker Paladin), races (OK, while I am sure there are half-gnome/half-goblins, and I am sure that would be a very interesting character, I am only allowing that if the entire group is willing to accommodate you as well because their characters are going to have a harder time with NPCs with your character around….), etc. If I don’t know the group, I prefer to sit in on a session or two while they play so that I can get to know the players first rather than just “Blind DM’ing”. Although that is fun too!!

Session 0 is when I meet some new friends (even if I am playing with my old friends).

Things I cover in Session 0:

1. Description of General Flow, and how I run a game: Good game flow is important. everyone has the right to express opinions and wants for the game, everyone can bring up rules/interpretations, BUT the GM will make a "snap decision" in the moment, and that's a final ruling for right then; "snap decisions" can be discussed outside game session time - it's possible that the ruling may change for future occasions .
2. Division of Responsibilities/Rights: Players control their characters, DM controls the NPCs and World, Host controls the playing space and social rules there ( e.g. please no swearing around the host's small children running through the room).
3. Players' Expectations: What kind of adventures do you want to play in? Name 3 books and/or movies you really liked or thought were influential on you. What kind of adventures would you find boring, or un-fun ( "Grog goes shopping!(tm)" ).
4. Player Boundaries & How to Handle Them: What topics/themes/events are you uncomfortable with? Never want to see in the game? ( graphic violence, adult content,  pro and anti religious themes, etc. ). It's your responsibility to bring issues to the DM; it's the DM and the groups' responsibility to be aware of them. No one's limits are "dumb" - respect theirs, they'll respect yours.
5. Table Game Rules ( discussion of and group consensus ): Critical hits and misses? "gritty realism" rest rules? Spell point variants? Popcorn Initiative? etc.
6. Table Etiquette: "Don't be a Dick", no texting/emailing/social media, no lengthy off-topics comments/discussions, devices ONLY if they are character sheets and/or source books. Step away from the table if you NEED to do something non-game-related. 
7. Game Etiquette: Meta-gaming, Murder Hoboism, Sharing the Spotlight, etc.
8. Level of "Realism" discussion and group consensus: Gritty realism vs. High Fantasy
9. Setting Description & World Background
10. Character Creation: Restriction: must create a character who would a) want to go adventuring and b) would want to go adventuring in a GROUP. 
11. Party Creation: how do you all know each other? Why are you adventuring together?
12. Party introduction scene & Initial "adventure hook"

That usually will take up all the time I have for session 0. 

It's sets a group consensus for the table etiquette, campaign type,  player and DM expectation, and sets things up to "hit the ground running" for Session 1.

Brilliant list Vedexent. Captures pretty much all in my view. The thing I would add is rather something to considering in between session 0 and 1: story hooks for each PC. Given point 10-12, add a bit more depth to something about the PC that the DM is free to use during the campaign to both involve and invest the PC but also create memorable moments for the players. This can mean that the DM limits the options somewhat in order to, for example, set up a link to NPCs or groups that are important later in a campaign (but seem irrelevant for now). 

The above might not be the easiest for a new GM, but worth trying. You can do it as part of session 0, but keeping it between each PC and the DM you get a possible fun surprise for other players as well when new information reveals certain things about the other PCs. 

Quote from Eggnot >>

Brilliant list Vedexent. Captures pretty much all in my view. The thing I would add is rather something to considering in between session 0 and 1: story hooks for each PC. Given point 10-12, add a bit more depth to something about the PC that the DM is free to use during the campaign to both involve and invest the PC but also create memorable moments for the players. This can mean that the DM limits the options somewhat in order to, for example, set up a link to NPCs or groups that are important later in a campaign (but seem irrelevant for now). 

The above might not be the easiest for a new GM, but worth trying. You can do it as part of session 0, but keeping it between each PC and the DM you get a possible fun surprise for other players as well when new information reveals certain things about the other PCs. 

Thank you :)

And I agree with your other points.

Typically I maintain an email discussion with players between session 0 and session 1, which allows the player, and myself, to flesh out some background story, and for me to jot down some notes, and some possible story hooks. However, that's really "one-on-one" between DM and Player, no need for a group session, hence the email.

I also typically weave those aspects into the world as much as I can. I've had whole secret organizations spring into existence because I needed one for a player background. In fact, the major story arc for levels 3-10 of my current campaign has come about because of interaction between player backstory collisions, some actions that the party initiated in their beginning adventures, and me writing some "black hats" pulling strings in the background to explain those events. Suddenly I had a Villain ( or villainous organization ), with a goal, and an agenda, whose actions were impacting the party, and hey, presto - Campaign Arc!

It’s probably been said before, but have everybody set expectations for what they want most out of the game. It also helps to list the three pillars of the game (roleplaying, combat, exploration)  in terms of most favorite to least favorite. Example:

I enjoy roleplaying the most, followed by exploration, followed by combat. Exploration and combat are both closely tied for second place though. Even that little bit right there helps to define what I want out of the game, and what I would be bringing to the table

I don't think I have ever done a session 0. I take alot of time with my players leading up to the first game  helping with backstory, and tone so when they get to the first game they know everything they need to.

I think that counts - You're just breaking up your session 0 into lots of little ones.I'd be willing to bet beer money that the result is the same; that you end up going through all the things - either explicitly, or implicitly - with your players that some people shove into session 0.

You're just doing private tutoring, instead of a group seminar :)

I don't think there's anything special about "Session 0", it's what it accomplishes that's important. And if you have players that know each other well, lots of what's in my list is redundant; everyone already knows what everyone wants/dislikes, how the GM runs, etc.

I think the idea behind Session 0 is to be able to take a group of relative strangers and/or people who have never played an RPG ( or at least never played together ), and set expectations ahead of time so-as not to run into ( as many ) issues down the road.

With this current resurgence of RPGs ( and Dnd 5e in particular ) where we have a flood of new players arriving on scene - thanks to the success of shows like Critical Role, Dice Camera Action, and High Rollers  - it's a handy tool to have in your back pocket.

Quote from VanZoeren >>

It’s probably been said before, but have everybody set expectations for what they want most out of the game. It also helps to list the three pillars of the game (roleplaying, combat, exploration)  in terms of most favorite to least favorite. Example:

I enjoy roleplaying the most, followed by exploration, followed by combat. Exploration and combat are both closely tied for second place though. Even that little bit right there helps to define what I want out of the game, and what I would be bringing to the table

Possible side note for another thread entirely - but I find that while Combat can quickly "go off the rails" and become tactical war-gaming, that Combat can become really intensely role-playing - when players make sub-optimal choices based on their Character, where in-combat chatter is done in character, etc. 

It takes the right kind of group to do that, however.

I'm not sure that thinking of the "three pillars" as separate aspects  is the best approach, and it's a recent goal of mine to try and collapse elements together: combat with intense role-playing, a running battle where exploration and combat can be rolled into each other, etc.

@Vedexent:  I have managed one time in nearly 30 years as a DM, in Myth Drannor, to have a single session that was absolutely perfect in that the Characters were continuously harried by monsters, and had to plan, run, hide, and fight all at the same time (for nearly 2 hours) and when they finally reached the "safety" of a semi-collapsed building, the players and myself were all like: "WHEW!" This night stands alone in my memory for several reasons and your goal resonates with that memory. I did not strive for that blend that night but rather played the box set as it was written and somehow, the stars just lined up for us. Everyone in that group talked about that night with new transient gamers and new groups; and even now I could call any one of them up and say "You remember that night we played in Myth Drannor?" and even though there had been a few before and quite a few since, they would instantly know to which night I was refering.

I have come close a few other times (admittedly through a bit of metagaming) to reaching that same level of play and I have concluded that I am only a fraction of the requirement. I believe it was that group, that box, and an unknown synergy that developed that night that allowed us to reach the point where the was no separation between the Role, the Fight, and the need to find shelter (the exploration).

I wish you the best of luck with your goal and would love to read a story of how you managed.