If your OS is too old for the current version of Final Cut Pro, Apple will usually prompt you with a dialog box stating: "The current version requires macOS [X] or later, but you can download the last compatible version."
: Apple offers a full-featured 90-day free trial of the latest version of Final Cut Pro. This allows you to test the "full piece" of the software before committing to a purchase. final cut pro 1046 download exclusive