Hi, native speaker here. Since I don't know exactly your level I'm going to recommend you some easily available (or at least I hope so) children's books.
Check out Geronimo Stilton / Tea Stilton book. They are characters in children's books (there is also a cartoon). Geronimo is an anthropomorphic mouse who is the director of a publishing press. Tea is his sister, an adventurous journalist (she mostly appears in the Tea Sisters series(es), about a group of college girls).
You will find books in any genre you like and some of the words are highlighted / written with funky fonts to catch children's attention, which will probably be helpful since you want to improve your vocabulary. Some books are quite short (the yellow ones) and others are a bit longer (like the Viaggi nel regno della fantasia or the Viaggi nel tempo series) but still full of illustrations.
The Tea Sisters also have shorter (the purple ones) and longer adventures.
Or maybe V come Valentina. They are the adventures of Valentina, a very normal Italian girl. In the first batch of books she is an elementary school child (cause it was written by an elementary school teacher) but then she grows up in later books until she becomes a teenager I think.
In all these series there are MANY books, at least a hundred each, so you should be able to get a lot of practice.
Otherwise, we have so many Mickey Mouse comic books made in Italy! Look up Topolino and maybe try to read the 1-page comics at first. There are usually a couple in every Topolino issue (weekly) (there are also bigger volumes under other names that come out monthly and special editions) (also a superhero series for Paperinik aka Donald Duck) (please note that the most interesting stories are about Donald Duck & co).
If you are feeling adventurous, you might try Un leone su su ruote, which is about a tween (I think) getting discovering that he has a talent for minimoto (small bikes for tweens basically) and signs up to competitions under a fake name for a variety of reasons.
Or maybe the fantasy series La bambina della sesta luna, about alchemy and set in Venezia (5 volumes in the original series).
Or La porta del tempo, which has too many books and stops making sense after a while but starts off great. A bit of mystery, a bit of fantasy, Gravity Falls vibes.
I read a lot of fantasy as a kid, haha.
Let me know if you'd like to know something else or need other recommendations!
