Mom and daughter looking to restore 74 Dart or Duster

Welcome aboard!
As far as advice you've come to the right place lots of people willing to help.
As far as parts:
There's the classified forum on the site
Site sponsors
There are many companies that handle parts:
Classic Industries
Year One
Van's Auto
Dante's
Layson's
Just to name a few.

Oh! Car show swap meets are also a good source too.

You and your daughter have fun working on your project which ever one you choose.