User @UncleFester, some time ago, wrote a thorough beginner’s guide for setup of FreeNAS 9.10. It seemed to me like something that belonged on a more permanent, and user-editable, location, so with his permission I wiki-fied the guide and have been hosting it on my server. I’ve recently update it to match the GUI for TrueNAS CORE 13. The guide can be found at:
https://wiki.familybrown.org/fester/
I hope it will continue to be helpful.
As “wiki” suggests, this site is open for edits–feel free to register for an account to add/edit/update.