Is there an authoritative book to start with?

No, but there are a lot of very good books.

Several that I would recommend a
- Trout by Ray Bergman. You can find
inexpensive, but very worthwhile versions of this book out on Amazon.

- Hatches II by Caucci & Nastasi

- Caddisflies by LaFontaine

- The Curtis Creek Manifesto - a "comic book", but very entertaining and
informative read.

You will get recommendations for dozens of "authoritative" books, and indeed,
many of those will be very good books.

As to gear, start and stay simple.

Go light.

Don't buy a bunch of "gizmos", you just don't need them.
-- so much fishing, so little time --
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