Practice the art of dodging. Equipment load is gone in Bloodborne and all characters are quick, so use that to your advantage.

The dodge is a sidestep when locked on and a traditional roll when not locked on. Both can be effective in different situations.

Keep an eye on your stamina. You don't want to endlessly hit an enemy and then run out, leaving yourself open to a big attack.

The big enemies in front of the elevator to Father Gascoigne (near the Central Yharnam lamp) always drop blood vials. So do the werewolves on the bridge above. If you need to farm for blood vials, those are good spots.

Don't focus too much on bloodtinge or arcane when leveling up early in the game. Those stats are better served for late game play or NG+.

You can parry attacks with your gun in Bloodborne. Wait until the moment right before an enemy hits you and then shoot. This will stagger the enemy, allowing you to get close for a visceral attack.

Remember to transform your weapon. The transformed version often does extra damage and has some great moves for crowd control and/or extra reach.

Try out all the different weapons and find one that suits your playstyle best. It's less about numbers and more about the moveset you find most comfortable.

If you're struggling with a particular area, take a look at your armor. Some outfits are better for poison, frenzy, etc.

Many items, such as molotovs, scale with the arcane attribute.

Arcane scaling on a weapon affects elemental bloodgems that are inserted into that weapon. Otherwise it does nothing.

You can still backstab enemies, you just have to stagger them first. Stealth + charge attack is a great way to quickly dispatch tough foes.