Base TeX template for class notes.

base.tex

\documentclass[12pt,utf8,twocolumn,a4paper]{article}
\usepackage[utf8]{inputenc}
\usepackage[brazilian]{babel}
\usepackage{mathtools}
\usepackage{amsmath}
\usepackage{graphicx}
\usepackage[margin=2cm]{geometry}

\newcommand{\sidenote}[1]{\marginpar{\footnotesize{#1}}}
\newcommand{\drawspace}[2]{\setlength{\unitlength}{#1}\begin{picture}(1,1)\end{picture}\\{\footnotesize #2}}
\setlength{\marginparwidth}{1.2in}
\allowdisplaybreaks

\numberwithin{equation}{subsection}

\title{\textbf{Título}\\Subtítulo}
\author{Leonardo Koch Kewitz}
\date{\today}

\begin{document}
\maketitle

\end{document}