\documentclass[12pt]{standalone}
\usepackage{amsmath,amssymb}
\usepackage{newtxtext,newtxmath}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}[scale=1.5]
\draw[dashed] (-3.8,-2.4) grid (3.8,3.8);
\draw[->,thick] (-3.8,0) -- (3.8,0) node[below left] {Re};
\draw[->,thick] (0,-2.4) -- (0,3.8) node[below left] {Im};
\draw (0,0) node[below left] {$0$};
\draw (0,1) node[below left] {$\mathrm{i}$};
\draw (1,0) node[below left] {$1$};
\draw[fill=black] (3,2) circle (2pt) node[above left] {$3+2\mathrm{i}$}; 
\end{tikzpicture}
\end{document}