Btukfyl

I'm new to Latex and I'm making a big document with a lot of sections, subsections etc. Could anyone find out why the sections numbering doesn't appear in the PDF?
Here is my preamble:

PassOptionsToPackage{unicode=true}{hyperref} % options for packages loaded elsewhere

PassOptionsToPackage{hyphens}{url}

%

documentclass{article}

usepackage{blindtext}

usepackage[T1]{fontenc}

usepackage[utf8]{inputenc}

%makeatletter

%patchcmd{ttlh@hang}{parindentz@}{parindentz@leavevmode}{}{}

%patchcmd{ttlh@hang}{noindent}{}{}{}

%makeatother

usepackage{lmodern}

usepackage{amssymb,amsmath}

usepackage{ifxetex,ifluatex}

ifnum 0ifxetex 1fiifluatex 1fi=0 % if pdftex

  usepackage[T1]{fontenc}

  usepackage[utf8]{inputenc}

  usepackage{textcomp} % provides euro and other symbols

else % if luatex or xelatex

  usepackage{unicode-math}

  defaultfontfeatures{Scale=MatchLowercase}

  defaultfontfeatures[rmfamily]{Ligatures=TeX,Scale=1}

fi

% use upquote if available, for straight quotes in verbatim environments

IfFileExists{upquote.sty}{usepackage{upquote}}{}

IfFileExists{microtype.sty}{% use microtype if available

  usepackage{microtype}

  UseMicrotypeSet[protrusion]{basicmath} % disable protrusion for tt fonts

}{}

makeatletter

@ifundefined{KOMAClassName}{% if non-KOMA class

  IfFileExists{parskip.sty}{%

    usepackage{parskip}

  }{% else

    setlength{parindent}{0pt}

    setlength{parskip}{6pt plus 2pt minus 1pt}}

}{% if KOMA class

  KOMAoptions{parskip=half}}

makeatother

usepackage{xcolor}

IfFileExists{xurl.sty}{usepackage{xurl}}{} % add URL line breaks if available

IfFileExists{bookmark.sty}{usepackage{bookmark}}{usepackage{hyperref}}

hypersetup{

  pdfborder={0 0 0},

  breaklinks=true}

urlstyle{same}  % don't use monospace font for urls

usepackage{graphicx,grffile}

%makeatletter

defmaxwidth{ifdimGin@nat@width>linewidthlinewidthelseGin@nat@widthfi}

defmaxheight{ifdimGin@nat@height>textheighttextheightelseGin@nat@heightfi}

makeatother

% Scale images if necessary, so that they will not overflow the page

% margins by default, and it is still possible to overwrite the defaults

% using explicit options in includegraphics[width, height, ...]{}

setkeys{Gin}{width=maxwidth,height=maxheight,keepaspectratio}

setlength{emergencystretch}{3em}  % prevent overfull lines

providecommand{tightlist}{%

  setlength{itemsep}{0pt}setlength{parskip}{0pt}}

setcounter{secnumdepth}{-2}

% Redefines (sub)paragraphs to behave more like sections

ifxparagraphundefinedelse

  letoldparagraphparagraph

  renewcommand{paragraph}[1]{oldparagraph{#1}mbox{}}

fi

ifxsubparagraphundefinedelse

  letoldsubparagraphsubparagraph

  renewcommand{subparagraph}[1]{oldsubparagraph{#1}mbox{}}

fi

% set default figure placement to htbp

makeatletter

deffps@figure{htbp}

makeatother



newcommandblankpage{%

    null

    thispagestyle{empty}%

    addtocounter{page}{-1}%

    newpage}

    usepackage{times}

usepackage[margin=1.5in]{geometry}

date{}

begin{document}



input{part1ch1}

part1ch1.tex looks like:

section{text...}