Project vs. Document How Best to Tackle a Saga?

Sorry, I am still a little confused about Papyrus Author. I am trying learn it, but don’t always have the time to stick with it. So I tend to forget things I already learned about it when I have a long break away from it. At the moment I am trying to wrap my head around which is better, to create a project or a document. I’m going to assume that multiple documents can be added to a single project, yes?

I’ve been trying to figure out how best to tackle my story idea - Its kind of a saga in fan fiction. It tells the Harry Potter stories from Hermione’s prospective. It is called Catching Her Heart and spans from Hermione’s 1st year to the Battle of Hogwarts. Because of the age changes in the story I am not really sure how to do the character sheets for the age section either. I titled it Catching Her Heart because it is a slow burn friends to romance between Oliver Wood and Hermione Granger.

You can always turn a document into a project later. But if you already know you’re going to need a characters database, it makes sense to start with a project.