I would start with stories, so fairy tales or children's books.

Ciao Gloria, have a look here: https://www.almaedizioni.it/it/catalogo/scheda/il-signor-rigoni-pdf/ I hope you'll enjoy this books! :)

Hi Anastasia, I recommend buying this textbook, I used to own one and it helped teaching little foreign kids: “Italian Made Simple” by Cristina Mazzoni It's nice and simple to understand, but very detailed and rich I think that's for you. Feel free to contact me if you have any doubts or if you'd like to learn some Italian with me! :)