When you first arrive in the strange village that gives Resident Evil Village its name, you will be set upon by a horde of werewolves who will eventually leave for unknown reasons. After that, you will need to try and make your way into the castle.
To do this, you will need two stone crests to place in a wall. This will then open a secret door, letting you into the castle grounds. The Maiden Crest and Demon Crest can both be found in the village. For the maiden crest, simply head right through some iron gates, into a building with blue trim and you will find it rest on a table in there. The Demon Crest requires far more work.
Once you have the Maiden Crest, leave the building and go through a broken gap in the wall. This leads to a hut on the left, and a grass hill on the right. Explore the hut and loot all the items, then quickly make your way up the hill. This is swarming with werewolves, but you can deal with them easily by just reach the top and interacting with the wide gate there. Some NPCs will call out from the right, so head in the door and speak with them.
After the dialogue is over, jump through the window in the back, up onto the blue crate to the left, and over the wall. Loot the outhouse, then go down and open the gate to let in the other NPCs. On the right, you will find a small wooden box that has the Demon Crest inside, but you cannot grab it yet.
Let all the dialogue play out and you will end up inside the house. There is lots of dialogue and story progression here that we will not spoil. Eventually, you will find yourself trapped and needing to escape the house. You will be in a garage so explore it fully and go into the kitchen there. In a drawer to the left of the sink, you will find some track keys. Interact with them and turn them around to look at the back where you can press a prompted button to retrieve a screwdriver. This is an important item that you will need to get the Demon Crest.
Loot the rest of the room and make your way back to the car where more linear storyline will play out. Once again we do not want to ruin these events for you. There are no choices to be made, and you can only ever go in one direction. When you find yourself back outside the house, use the screwdriver to get the Demon Crest, then return to the wall and place both crests in it to open the gate to the castle.