\documentclass[numbering=fraction]{beamer}
\usepackage[utf8]{inputenc}
\usepackage{blindtext}
\usetheme[progressbar=frametitle]{metropolis}
%Define colors
\definecolor{wuppergreen}{RGB}{137, 186, 23}
\definecolor{background}{RGB}{255,255,255}
%Adding logo to title page
\titlegraphic{\includegraphics[width=3cm]{Unilogo_schwarz_T3.png}}
%Adjust color theme
\setbeamercolor{frametitle}{bg=wuppergreen}
\setbeamercolor{title separator}{fg=wuppergreen}
\setbeamercolor{footline}{fg=gray}
\setbeamercolor{progress bar}{fg=black}
%Adding footer
\setbeamertemplate{frame footer}{\insertshortauthor~(\insertshortinstitute)}
%Set parameters for title page
\title{Title}
\author[Author]{Author\\\textbf{Meeting}}
\institute{Bergische Universität Wuppertal}
\date{\today{}}
\begin{document}
\begin{frame}[plain]{}
\maketitle
\end{frame}
\section{New Section}
\begin{frame}{Some Blind Text}
\blindtext
\end{frame}
\begin{frame}{Some Items}
\begin{itemize}
\item Item 1
\item Item 2
\item Item 3
\begin{itemize}
\item Subitem 1
\item Subitem 2
\end{itemize}
\end{itemize}
\begin{enumerate}
\item Number 1
\item Number 2
\end{enumerate}
\end{frame}
\begin{frame}{Some Boxes}
\begin{block}{Simple Block}
This is a sample text
\end{block}
\begin{exampleblock}{Example Block}
This is a sample text
\end{exampleblock}
\begin{alertblock}{Alert Block}
This is a sample text
\end{alertblock}
\end{frame}
\end{document}