Dunk the papermaking mould and deckle (the screen frame) into the vat and pull it up slowly, keeping it level to catch an even layer of pulp.
Combine a handful of soaked paper with 2-3 cups of water in a blender. Blend until smooth. Add more water if the consistency is too thick—it should look like thick smoothie or oatmeal.
How to Make Paper with Kids: A step-by-step tutorial - TinkerLab
I can give you more specific tips for a better finished product!
Tear or cut scrap paper into small pieces (under 2 inches) and soak them in hot water for at least an hour, or overnight for firmer papers.