By reading this book you can learn many things, like how to use people-first constructions, gender-neutral nouns, and that run-on sentences put together with commas are now cool, so if that's your idea of a good thing, knock yourself out, another thing you can learn is how to use trendy internet abbreviations like IRL (in real life), which will be forgotten in six months from the date of publication, the book is based on language as people use it IRL, and that's where I'd go to find every conceivable error and misconception, and some that aren't.

See "Dreyer's English" for better guidance.