As I understand it, all I need to add is the Gutenberg Plugin. Am I right?
No, you don’t need to install the Gutenberg plugin.
Gutenberg (or the Block Editor) is now the default editor that ships with WordPress and no plugin is required to use this.
The separate Gutenberg Plugin is more or less the testing ground for new features of the editor under development before those features are integrated into the built-in Block Editor. So you’ll only need to install the Gutenberg plugin if you’re a theme/plugin developer who needs to test your code against the upcoming block editor features, or you’re the kind that wants to stay at the bleeding edge.
And I do NOT want to create any Static Pages.
You may likely have to create a few “static” pages: About, Contact, Privacy, etc. That said, you don’t need any additional tool to create a WordPress “static” page: you create a PAGE visually just as you create a POST… from the same Block/Gutenberg Editor.
Good luck with your project!