\documentclass[a4paper,landscape]{article}

\usepackage[landscape,top=0cm,left=0cm,bottom=0cm,right=0cm]{geometry}
\usepackage{tikz}
\usetikzlibrary{matrix}
\usetikzlibrary{backgrounds}
\usetikzlibrary{intersections}
\usetikzlibrary{positioning}
\usetikzlibrary{calc}

\pagestyle{empty}
\setlength{\parindent}{0cm}

\tikzset{outer/.style={remember picture}}

\newcommand{\checkbox}[1]{\tikz[label distance=0.2cm]{\node[label={east:\large{#1}},draw,very thick,rectangle,text height=0.5cm,text width=0.5cm,inner sep=0cm] at (0,0) {};}}
\newcommand{\emptycheckbox}{\tikz{\node[text height=0.5cm,text width=0.5cm,inner sep=0cm] at (0,0) {};}}

\begin{document} \sffamily
\begin{tikzpicture}[outer]
    \begin{scope}[local bounding box=headarea]
        \path (current page.north west) ++(1cm,-1cm) coordinate (OL) -- (current page.north east) ++(-1cm,0cm) coordinate (OR) node[midway,below=0.5cm] {\textbf{TEILNEHMER - / INNENLISTE}};
        \matrix (options) at ($(OL)+(0.5cm,-1cm)$) [matrix of nodes, column sep=0cm,row sep=0.5cm,nodes in empty cells, every node/.style={inner sep=0cm,align=left,text width=6.2cm}, anchor=north west] {
            \checkbox{Jugendbildungsmaßnahme} & \checkbox{Gruppenleiter/innenschulung} & \checkbox{Ferienkolonie} & \checkbox{Freizeitnaßnahme} \\
            \checkbox{Int. Jugendbegegnung}   & \checkbox{politische Jugendbildung}    & \checkbox{Projekte}      & \emptycheckbox              \\
        };
        \node[align=left,inner sep=0cm,anchor=west] at (options-2-4.west) {\tikz{\node[draw,very thick,rectangle,text height=0.5cm,text width=0.5cm,inner sep=0cm] (checkbox) at (0,0) {}; \draw[thick] (checkbox.south east) ++(0.2cm,0) -- (checkbox.south east -| options-2-4.south east);}};

        \node[anchor=north west] (org) at ($(options.south west)+(0cm,-0.5cm)$) {\large{Veranstalter:}};
        \draw[thick] (org.south east -| options-2-2.south west) -- (org.south east -| options-2-4.south east) node[pos=0.02,above=0.1cm] {\LARGE{aa}};

        \node[anchor=north west] (title) at ($(org.south west)+(0cm,-0.5cm)$) {\large{Titel der Maßnahme:}};
        \draw[thick] (title.south east -| options-2-2.south west) -- (title.south east -| options-2-4.south east);

        \node[anchor=north west] (datefrom) at ($(title.south west)+(0cm,-0.5cm)$) {\large{Datum vom:}};
        \draw[thick] (datefrom.south east -| options-2-2.south west) -- ($(datefrom.south east -| options-2-2.south east) - (1,0cm)$);

        \node[anchor=south west] (dateuntil) at (options-2-3.south west |- datefrom.south west) {\large{bis:}};
        \draw[thick,label={east:aaa}] (dateuntil.south east) -- (datefrom.south east -| options-2-3.south east);

        \path[fill=yellow] (datefrom.south -| OL) ++(0,-1.0) rectangle ($(datefrom.south -| OR) + (0,-1.5)$);
        \draw (datefrom.south) -- ++(4cm,-4cm);
    \end{scope}


    % \draw[red,ultra thick] (current page.north west) rectangle (current page.south east);
    \draw[thick,green] (headarea.north west) -- (headarea.south east);
\end{tikzpicture}

\pagebreak[4]

\begin{tikzpicture}[outer]
    \path (current page.north west) ++(1,-1) coordinate (OL) -- (current page.north east) node[midway,below=0.5cm] {\textbf{TEILNEHMER - / INNENLISTE}};
    \matrix[draw] (options) at ($(OL)+(0.5cm,-1cm)$) [matrix of nodes, column sep=0cm,row sep=0.5cm,nodes in empty cells, every node/.style={inner sep=0cm,align=left,text width=6.2cm}, anchor=north west] {
        \checkbox{Jugendbildungsmaßnahme} & \checkbox{Gruppenleiter/innenschulung} & \checkbox{Ferienkolonie} & \checkbox{Freizeitnaßnahme} \\
        \checkbox{Int. Jugendbegegnung}   & \checkbox{politische Jugendbildung}    & \checkbox{Projekte}      & \emptycheckbox              \\
    };
    \node[align=left,inner sep=0cm,anchor=west] at (options-2-4.west) {\tikz{\node[draw,very thick,rectangle,text height=0.5cm,text width=0.5cm,inner sep=0cm] (checkbox) at (0,0) {}; \draw[thick] (checkbox.south east) ++(0.2cm,0) -- (checkbox.south east -| options-2-4.south east);}};

    \node[anchor=north west] (org) at ($(options.south west)+(0cm,-0.5cm)$) {\large{Veranstalter:}};
    \draw[thick] (org.south east -| options-2-2.south west) -- (org.south east -| options-2-4.south east) node[pos=0.02,above=0.1cm] {\LARGE{aa}};

    \node[anchor=north west] (title) at ($(org.south west)+(0cm,-0.5cm)$) {\large{Titel der Maßnahme:}};
    \draw[thick] (title.south east -| options-2-2.south west) -- (title.south east -| options-2-4.south east);

    \node[anchor=north west] (datefrom) at ($(title.south west)+(0cm,-0.5cm)$) {\large{Datum vom:}};
    \draw[thick] (datefrom.south east -| options-2-2.south west) -- ($(datefrom.south east -| options-2-2.south east) - (1,0cm)$);

    \node[anchor=south west] (dateuntil) at (options-2-3.south west |- datefrom.south west) {\large{bis:}};
    \draw[thick,label={east:aaa}] (dateuntil.south east) -- (datefrom.south east -| options-2-3.south east);

    \path[fill=yellow] (datefrom.south -| current bounding box.north west) ++(0,-1.0) rectangle ($(datefrom.south -| current bounding box.south east) + (0,-1.5)$);

    \draw (datefrom.south) -- ++(4cm,-4cm);

    \draw[red,ultra thick] (current page.north west) rectangle (current page.south east);
\end{tikzpicture}


\end{document}