I've tried to put a picture, title and author in the same page but I the command doesn't work. Furthermore the command \maketitle doesn't work now and I don't understand why. My idea is to aligne the picture in the top centre, che title right below centred and also the author, below title.
\documentclass[pt12]{article}
\usepackage{tabularx}
\usepackage{geometry}
\usepackage{amssymb}
\title{\textbf{Calcolo delle caratteristiche di un motore reale}}
\author{\begin{tabular}{rl}
\textbf{Gruppo:} & First Name \\ & Second Name \\& Third Name \\ & Fourth Name
\textbf{Classe:} & $5^{\circ}CI$
\end{tabular}}
\date{}
\usepackage{color}
\usepackage{afterpage}
\usepackage{graphicx}
\graphicspath{Immagini/}
\begin{document}
\maketitle
\begin{figure}
\includegraphics[scale=0.5]{../../Pictures/Nautico.jpg}
\end{figure}
\pagecolor{cyan}
\afterpage{\pagecolor{white}}

\begin{figure} .. \end{figure}to use\includegraphics. In fact, in this case you don't want it. Further,pt12in the documentclass options should be12pt, and\graphicspath{Immagini/}should be\graphicspath{{Immagini/}}. – Torbjørn T. Oct 09 '16 at 07:53