itch.io

Berry is from first area with slime enemies just the normal red fruits you get is what the fairy wants. Evie's book I believe you got to get from the shady vendor at night time. There is a Bartender you can ask for hints. As long as there is something to do he will give hints on where to go or what to do.

You get berries in random chests, in locations related to Celica's work.

As for the book, follow the plot using the bartender's hints. And read the characters' dialogues, there are hints there.