Thinking through the tutorial level they really tell/force-you-to-discover the important things.
Obviously there were signs on the ground that tell you what the buttons do. And that killing people will give you souls. You fight a ginormous demon and get slaughtered (in this game you will encounter things you are not ready for yet) You have to be able to climb a ladder. (There will be ladders) you face an archer and get nailed by some arrows. What the hell!? Oh, a shield. In this game the shield is so important it's the first thing you get.
Then you get your weapon, holy balls I can kill people faster! Having a better weapon helps out immensely! Oh, and they don't tell you how to equip it. You have to figure that out before you leave the tutorial level.
There's more. Some doors are locked - you'll need keys in this game. There will be traps in this game. Secrets may open up (boulder trap breaks the wall), you can use the Estus to heal, you may see items you can't get yet, there will be "friendly" NPCs, shortcuts can be found, etc.
"Levels" will "end" with a boss. You restart at the bonfire. Enemies can drop items.
And apart from the obvious stuff, one may glean that equipment is more important than level. (You don't level up at all, but shit's sure easier with the weapon and shield) I sure learned to respect that even the little cranky basic enemies can kill you, and that the dude with the better armor and weapon deserves more respect.
I think a person comes out of the tutorial knowing how to change equipment, knowing to appreciate how easy it is to die, and understanding keys, exploration, finding items, getting to the boss, etc.
I really appreciate that they "teach" you the game by making you do it, and without a little fairy helper stopping you every 30 seconds with another helpful tidbit. Maybe that's another thing they teach you - you're on your own, here, pal. Good luck.