How do I follow the AFD on the default 737-800? Can I use the autopilot to follow it? The learning centre isn't helpful at all so your help will be much appreciated.

I am not sure if any autopilot would track an NDB/ADF.In a windy condition, it could be a disaster. Check this out. http://www.navfltsm.addr.com/ndb-nav-adf-2.htmManny

There is no provision to "track" an NDB. They are simply lack the precision needed. That's like asking how to get high-fi stereo sound from an old Edison waxed phonograph cylinder... ;)