\documentclass[12pt,a4paper,oneside,openright]{book} %oneside versione segreteria
\usepackage[english,italian]{babel}
\usepackage[a4paper,top=2cm,bottom=2cm,left=3cm,right=2.5cm]{geometry}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{bm}
\usepackage{graphicx}
\usepackage{hyperref}
\begin{document}
\frontmatter
\pagestyle{plain}
\tableofcontents

\mainmatter
\pagestyle{plain}

%Primo Capitolo
\addcontentsline{toc}{chapter}{Introduzione}
\chapter*{Introduzione}

\end{document}