\documentclass[a4paper,11pt]{article}
\usepackage[polish]{babel}
\usepackage[utf8]{inputenc} 
\usepackage[T1]{fontenc}
\usepackage{fourier}
\usepackage{graphicx}



\begin{document}

\begin{figure}[!ht]
\centering
\includegraphics[scale=0.65]{demo.pdf}
\caption{Rysunek demonstracyjny do osadzania grafiki}
\label{fig:demo}
\end{figure}

\end{document}