Welcome to FlatRedBall-Spriter.
I'll assume you aren't here to figure out how to get or build the code. You want to use this thing, so I will help you. Start by ensuring you have the latest release
You will also need to download Spriter, which is a tool developed by the fine folks at BrashMonkey.
I highly recommend going through the tutorials on their Youtube channel too:
You don't have to have a phenomenal understanding of Spriter to be able to use this plugin. The UI is fairly discoverable, so it's ok if you want to jump right in to my tutorials!
Tutorials
Head on over to the tutorials section to get started!