R3: "lock onto enemy" It's good to use this to keep track of an enemy. but sometimes it's better to remain unlocked for camera/aiming reasons.
O: Circle performs a roll when not locked on and a dash when locked on. Dashing is essential to the game. dashes and rolls give you a small window of invulnerability to attacks. Dodges are the key to surviving enemies in this game.
Where are my blood vials when I have 20 and I pick up more? Extra vials and bullets go straight into storage. When you die, or visit a lamp they are automatically refilled from your inventory.
How to level up?
Leveling up happens in the Hunter's dream. You talk to the doll. She awakens after you meet the first boss "The Cleric Beast" for the first time. You pay her blood echoes to increase your stats by one point at a time.
What do I do with this gun? Its damage is low: Guns are used for the Bloodborne equivalent of Dark Souls' parry. Shoot the enemy with your gun at close range right before and enemy attacks and they will be stunned. During this stun press r1 to execute a visceral attack for high damage. This is an essential skill for quickly dealing with enemies that hit hard and fast.
Weapon transformations? pressing L1 causes your weapon to transform and have a different moveset. This is especially important when an enemy has a shield. attacking once and then pressing L1 will cause you to perform and guard break transformation attack. Experiment with transformations.
My weapon is broken or its durability is low. There is a workbench where you can reinforce (level up) your weapon or repair. It's in the house by the fire.
Backstabs? to perform a backstab, sneak up behind an enemy and hold R2 to do a charged attack. if it lands the enemy will be briefly stunned. press R1 for a high damage visceral attack animation.
Insight? Insight increases naturally as you explore the game and kill bosses. Insight is consumed when you summon co-op partners to help you in your fight.
Blood Echoes? Blood echoes are the currency of the Bloodborne. You use them to buy items (there is a merchant in the fountain in the Hunter's Dream) and to strengthen your weapon and to increase your stats. Every use of blood echoes is a trade off. Choose wisely!
Where did my Blood Echoes go? I died. Your blood echoes are dropped when you die. If you die again without retrieving them they are lost for good. They will either be in a mark on the ground near where you died (press X to retrieve them) or they will be picked up by a nearby enemy. When you kill this enemy they are regained. It's best to spend your Blood Echoes as soon as you reasonably can. Don't walk around with excess thousands and risk losing your sanguine fortune.
(Feel free to add to this. Can we get this stuff added to the OT or a post near the start? assuming people agree it's a good idea.)
The mods screwed up. I believe Bish was going to keep his up but Stump closed it when Robot Pants opened the 2nd one. Meanwhile, Bish closed the 2nd one for being late. It looks like they closed them simultaneously unknowingly.