I think we all have different ways of learning things.
If it were me, I would likely find a book with very basic, general 'how to' set up a loom (mine in particular although diverse floor looms have many similarities) and jump right in
Then, when hitting a snag or an unclear step, refer to the book...or as is more common now, ask a group or look for a video, etc. I would avoid, if possible AI information.
For me, hands on, combined with the written word and illustrations is my starting point for most new crafts.
My preference is stumbling along in private and seeing where that leads.
Most of all, allow learning something new to be fun!
A photo or description of the Harrisville would be helpful as others have mentioned...is it a floor loom? 4 harness? jack?
One of your books will likely have a glossary that would help ID the parts of your loom.
greatest luck and enjoyment