I am teaching my friend since last month. We are using Ohta-san's Method book. We are practicing happy birthday about two month so far. I choose this method book for him because it looked easy. Most method books of ukulele are difficult. If the book is good difficulty for you, it works very good and you learn fast. But it is too difficult, you can not learn, you may get even worse. This happens to us very often with ukulele method books. OP says that he's found good Hawaiian book and he want to learn classical guitar method on ukulele. I think they are more difficult than Hal Leonard Ukulele Method 1. Happy birthday is very good song for my friend. Even such easy song we've took about two month so far. I think the problem of OP is not American fork musics. The book may be just too difficult to him.