Unfortunately, there aren't many AHK experts around anymore these days. Someone may eventually have an answer for you, but a word of advice would be to try and get your follow and assist working before attempting to set up JAMBA. JAMBA is an add-on which assists multiboxers, but is a standalone add-on which doesn't perform any basic assisting or following.

Also, while I'm no AHK expert (and I didn't watch the video), a straight up copy and paste of a script rarely works because every person has their own personal information (keys, game paths, etc) set in the script itself. Usually, you will need to change something in the script so that it works for you on your computer.