Before you can install Spina, you need to have Ruby and Rails installed first. Here are a couple of excellent resources to do that:
If you're on a Mac you should something like
rbenv to manage different versions of Ruby.
You need a database to store all of your content. Spina CMS requires a PostgreSQL database. You can install it using several ways. If you're on a Mac we recommend using
homebrew so you can simply run
brew install postgresql.