I'm not an expert but I met this man in Amish country once who had a little whittling shop on a farm. All of his work was done with a single blade of a Swiss army knife. He's written a few books but after seeing his work, the company behind the Swiss Army Knife collaborated with him to write a book.
His book starts off slow and easy and works up into figures like roosters. Lots of nice techniques and tips shared as well. https://www.amazon.com/dp/1565239091/ref=cm_sw_r_sm_apa_i_S.X9FbHXAWRSA
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I started with this book, if you want easy animals this is book is for you: https://www.foxchapelpublishing.com/whittling-in-your-free-time.html
I got 2cm thick basswood (ready to use) and an electric jigsaw to make blanks. It saves hours.
If you want easy whittling projects this is a nice book too: https://www.amazon.nl/Lubkemann-Victorinox-Whittling-Easy-Make/dp/1565239091 (You may want to look for a local reseller instead of amazon).