Hi Mike,
At least you need a discovery function. That´s mandatory in 2.0 AFAIK.
See here:
You may debug this on command line with "cmk --debug -IIv "
Feel free to add print statements for debugging purpose but remove it as soon as it works.
The check function depends fully on your needs. Mandatory is at least one yield as you can see in the doc.
It also depends on where you want to run the plugin. If you want to run it direct on your monitoring server its better to write a special agent. Unfortunately there is no documentation for this, so you may look how its done in the official code and copy paste.
I hope that helps.
Michael