Ever feel like editing text? A nice, simple notepad application is Gnome Edit, officially known simply as gedit
Launch gedit from the Activities Overview (search for "gedit").
If you've used any text editor on a moderately modern computer, gedit will be immediately intuitive to you. It's a text editor, with icons at the top for quick saves, opening new files, searching, search-and-replace, and so on.
If you're looking for something more complex with more formatting options and functions, check out Open Office (otherwise known as Libre Office).