\documentclass{scrreport}

% force UTF-8 encoding even on legacy systems.
\usepackage[utf8]{inputenc}
% support accents 
\usepackage[T1]{fontenc}
% new german language support. 
\usepackage[ngerman]{babel} 
% support enumerate environment
\usepackage{enumerate}
% make refs clickable
\usepackage{hyperref}

% useful macros for math typesetting. Extends amsmath
\usepackage{mathtools}
% maths font support (\mathbb and \mathcal etc)
\usepackage{amssymb}
% theorem typesetting
\usepackage{amsthm}

% Language sensitive quoting
\usepackage{csquotes}

% more sophisticated bibliography support 
\usepackage[citestyle=alphabetic,bibstyle=authortitle]{biblatex}
\addbibresource{pfad/zur/biblatex/datei.bib}
% Commands to change bibliography style
\usepackage{phaistos}

% Use this package to be able to create other tex files for example
% for individual chapters and include them in the main document.
% Usage: \subfile{path/to/subfile}
\usepackage{subfiles}

\newcommand{\RR}{\mathbb{R}}
\newcommand{\QQ}{\mathbb{Q}}
\newcommand{\ZZ}{\mathbb{Z}}
\newcommand{\NN}{\mathbb{N}}
\newcommand{\CC}{\mathbb{C}}
\newcommand{\KK}{\mathbb{K}}

\newcommand{\set}[1]{\ensuremath{\left\{#1\right\}}}
\newcommand{\abs}[1]{\ensuremath{\left\lvert#1\right\rvert}}
\newcommand{\norm}[1]{\ensuremath{\left\lVert#1\right\rVert}}

\DeclareMathOperator{\id}{id}

% bold title italicized body
\theoremstyle{plain}
\newtheorem{theorem}{Satz}[chapter]
\theoremstyle{plain}
\newtheorem{corollary}[theorem]{Korollar}
\theoremstyle{plain}
\newtheorem{lemma}[theorem]{Lemma}
\theoremstyle{plain}
\newtheorem{proposition}[theorem]{Proposition}

% bold title, roman body
\theoremstyle{definition}
\newtheorem{example}[theorem]{Beispiel}
\theoremstyle{definition}
\newtheorem{definition}[theorem]{Definition}

% italicized title, roman body
\theoremstyle{remark}
% dont number remarks
\newtheorem*{remark}{Bemerkung}


\subject{Bachelor Arbeit}
\title{Titel der Bachelor Arbeit}
\subtitle{Untertitel}
\author{Your Name}
\date{\today}
\publishers{Universität Bremen}

\begin{document}

\maketitle
\begin{abstract}
    % HIER ABSTRACT HIN
\end{abstract}

\tableofcontents
\pagebreak

\chapter{Einleitung}
    % EINLEITUNG

\chapter{Kapitel}
% KAPITEL EINLEITUNG
\begin{definition}
    % BEISPIEL DEFINITION
\end{definition}

\begin{theorem}
    % BEISPIEL SATZ
\end{theorem}
\begin{proof}
    % BEISPIEL BEWEIS
\end{proof}

\begin{corollary}
    % BEISPIEL KOROLLAR
\end{corollary}

\section{Noch eine Überschrift}

\section{Zusammenfassung}

\pagebreak
\printbibliography

\end{document}

\documentclass[numbers=noendperiod]{scrartcl}

\usepackage[utf8]{inputenc}
% support accents 
\usepackage[T1]{fontenc}
% new german language support. 
\usepackage[ngerman]{babel} 
% support enumerate environment
\usepackage{enumerate}
% make refs clickable
\usepackage{hyperref}

% useful macros for math typesetting. Extends amsmath
\usepackage{mathtools}
% maths font support (\mathbb and \mathcal etc)
\usepackage{amssymb}
% theorem typesetting
\usepackage{amsthm}

% Language sensitive quoting
\usepackage{csquotes}
\usepackage{phaistos}

\newcommand{\RR}{\mathbb{R}}
\newcommand{\QQ}{\mathbb{Q}}
\newcommand{\ZZ}{\mathbb{Z}}
\newcommand{\NN}{\mathbb{N}}
\newcommand{\CC}{\mathbb{C}}
\newcommand{\KK}{\mathbb{K}}

\newcommand{\set}[1]{\ensuremath{\left\{#1\right\}}}
\newcommand{\abs}[1]{\ensuremath{\left\lvert#1\right\rvert}}
\newcommand{\norm}[1]{\ensuremath{\left\lVert#1\right\rVert}}

\DeclareMathOperator{\id}{id}

% Kopiert von https://tex.stackexchange.com/questions/290410/ugly-overline-on-some-characters
\makeatletter
\newcommand*\rel@kern[1]{\kern#1\dimexpr\macc@kerna}
\newcommand*\widebar[1]{%
  \begingroup
  \def\mathaccent##1##2{%
    \rel@kern{0.8}%
    \overline{\rel@kern{-0.8}\macc@nucleus\rel@kern{0.2}}%
    \rel@kern{-0.2}%
  }%
  \macc@depth\@ne
  \let\math@bgroup\@empty \let\math@egroup\macc@set@skewchar
  \mathsurround\z@ \frozen@everymath{\mathgroup\macc@group\relax}%
  \macc@set@skewchar\relax
  \let\mathaccentV\macc@nested@a
  \macc@nested@a\relax111{#1}%
  \endgroup
}
\makeatother

\renewcommand\Bar[1]{\widebar{#1}}
\renewcommand\bar[1]{\widebar{#1}}

\DeclareMathOperator{\Realteil}{Re}
\renewcommand{\Re}{\Realteil}
\DeclareMathOperator{\Imaginaerteil}{Im}
\renewcommand{\Im}{\Imaginaerteil}

\title{Übung XX}
\author{Vorname Nachname, noch ein Vorname, noch ein Nachname}
\date{\today} % Falls man rechtzeitig abgibt haha 
% \date{Tag vor Abgabetermin} sonst

\begin{document}
\maketitle

\section*{Aufgabe 1}

\section*{Aufgabe 2}

\end{document}