"Oh yes, pale blood...heh. Well, you've come to the right place, Yharnam is the home of blood ministration. You need only to unravel its mystery. But where's an outsider like yourself to begin? Easy, with a bit of Yharnam blood of your own. But first, you need a contract. Good, all signed and sealed. Now, let's begin the transfusion. Oh don't you worry. Whatever happens, you may think it all a mere bad dream." (Laughs)
I've seen this dialogue in plenty of pre-release content, but as this is the opening cutscene of the game, this is likely to be as much directly told to us as we are going to get before being thrown into the world. From this, I get that Pale Blood will be a big deal, and that things are going to get crazy. The transfusion is not pale blood, but it is something we are seeking, and to start we need some Yharnam blood. Then, the opening shows us a wolf beast coming at us (the intentions are unclear to me, it doesn't seem aggressive or friendly) and the messengers choose us to be a hunter. I can't be certain if these events are symbolic in a dream or if this truly happened after passing out from the transfusion. My feeling is that it is symbolic of the messengers intervening and keeping the wolf beast, representing the Scourge, from us, and choosing us as a hunter. To be honest, I'm not sure if it ultimately matters either way.
From all of this I have plenty of questions, but there is one question here that sticks out to me:
Why are we seeking Pale Blood? We are coming into the narrative media res, with our previous actions being unclear and our motivations remaining a mystery. This is intentional (to what end I am still uncertain), but our starting apparel provides some clues:
Hood worn upon awakening to the nightmare