Hi @keithpjolley, and welcome to the community!
Are you just looking to play with exiting notebooks offline, or are you wanting to author them too?
Have you seen this:
Basically, you can run any notebook offline just by downloading the code as a tarball, unzipping it, throwing up a local serverref1, ref2, and then double opening the index file.
Does this help, or am I misinterpreting your question?