Go to the lumber yard and buy some boards suitable for boardbows-Oak, Hickory, Ash etc. Forget the backing for now, and don't worry about wood type-anything will work for now.........read and do searches on pertinent stuff-lots of buildalongs here.
Go to george tsoukalis site-I may have misspelled-you'll find it anyway. Start doing stuff-assemble tools, and get busy tillering.
The first half dozen or more are going to break anyway; but that is how we learn. Then, and only then, call somebody like Ted at Raptorarchery.com and get a proper stave.