Well... I will have to disagree on them being aggressive, some of them are picky eaters, shy and gentle souls.
the book is great though!

There are are lots of frogs to pick from, that would be considered good for beginners. The question is what do you want from ownership of one? Interact, watch them eat, do you like little and cute or big and fat. Big and fat usually don’t move much as they are older.

In general “pixies” a not difficult to keep, but you will really need to keep up cleaning poops. They stink..... badly.... and they are big