Spina is a CMS for Rails 6.1. If you want to get started quickly, create a new Ruby on Rails app with a PostgreSQL database and ActiveStorage enabled and follow these instructions:
Add the following line to your Gemfile:
gem 'spina'
Run the installer to start the setup process:
rails spina:install
The installer will help you create your first user.
Then start rails s and access Spina at /admin.