In the initial high-level planning in the Roadmap, you may not want to care about using the types (Epics, Stories e.t.c). Instead you may create all the draft activities as Notes. Notes can afterwards be converted to specific types in the detailed planning .
Notes are visible in the Storymap Tree like all other items. If they are created via the Roadmap, they are placed under the Inbox Folder in the Functional Folder. You may also create Notes below Epics directly in the Storymap or Outline views.
Why Notes should be converted to other types?
Notes are meant to be used in the first draft planning. They are easy to delete, if you change your mind about the planning activities. Notes cannot have children in the Storymap Tree (like Epics do), and they do not have a state. This means that you cannot set the Note to e.g. “Ready” or “Done”.