Forms to render "Guide in steps" or not?

[nilamo]

What is the best way to build this kind of Django project?

That's entirely subjective. Personally, I'd start with building the backend database, because I like tables. Then I'd put some test data in them. Then I'd start with authentication/authorization to get a working login/logout page. From there, I'd just display the contents of the db. Once I start looking at the data, and how to display, I might realize the database needs some structural changes. Once I get it to where I want to be, adding tasks/groups/guides is the easy part, because you already know exactly what format you need things to be in.