Write Revit file size to Instance parameter

Trying to write my first Dynamo script and very new to Dynamo. I would like to be able to ready some information from my Revit file and report it to instance parameters inside a family.

I am looking to read the file size from the current file, #warnings, and #unused families to create a Dashboard in a view. Not sure exactly how to write this or how Dynamo writes this but I have attached a screen capture of where I started and input would be helpful.

Ken!

You must have a parameter to write the file size to…