Re: Which fly for beginner?
I think the book is intended to follow a sequence of skills in tying. Some of the patterns depend on knowing the techniques in previous flies. Start at the front of the book and review the skills you have. If you don't know how to do something, try tying some of the flies that involve that technique. You will get more from the book if you proceed in this manner. The book is about tying technique opposed to a list of recipes.
I think the RS2 is an easy tie, but as in most flies it is a matter of proportion. Tie them thin. You may also be interested in variations. There are a lot of them.
Tying is fun and challenging. Good Luck.