Thank you for your help. Greetings Steph
closed as unclear what you're asking by Jacob Peattie, mmm, bosco, TheDeadMedic, shanebp Aug 9 '18 at 18:54
Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.
You're not supposed to modify the Dashboard.
It's recommended to create custom post types for content organisation and a top-level feature plugin for more complex options and settings. You can also use the Customizer to allow theme changes. A theme might already have these settings, so you could add some meta boxes with general help and how-to tutorials. You can also change the admin theme.
Note that a major WordPress version is coming really soon - 5.0 - and a feature plugin to make the admin theme dark is already submitted for consideration in core. Any Dashboard-changing plugin you might find, could be invalidated by this major version.
Also note that any Dashboard-changing plugin you might find is usually based on hacks and styling overrides.