Full video below.
There is one Journal Page for each of the locations/rituals/questions in the game.
Some locations have additional questions and those will have a separate page, even if they’re associated with a location.
Take photos, record audio, and collect items to add to your journal page. Each of these you collect will automatically be added to the KEEPSAKES specific to that page.
In order to access the KEEPSAKES to add to a page, hit the button that is specific to your console/pc. It should be shown in the red circle below, left of the word KEEPSAKES.
When you have collected enough items, the game will start to add Quotes and Decorations that you can add to your page as well. Items added can be resized and rotated using the dpad.