How to put 2 cols in landscape oriented page?, 1col for 1figure, other for comments?

Question

How can I obtain any similar to the image?

I was trying with similar things to

---

\documentclass[12pt,a4paper,x11names,landscape]{article}
\usepackage{lipsum,mwe}
\usepackage{incgraph,graphicx}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[spanish]{babel}
\usepackage{multicol}

\begin{document}
This is the 1st page of \jobname, with ONLY 1 col.


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\clearpage
\begin{multicols}{2}
\begin{figure}
  \centering
  \includegraphics[width=0.40\textwidth]{example-image-a.eps}
  \caption{forma02}\label{forma02}
\end{figure}

And now, in the rigth column, I want to explain the letter A.\\

A is the first letter of the alphabet.
\begin{itemize}
  \item because YES
  \item because B is the 2nd
  \item and finally, because C is the 3rd.
\end{itemize}
\end{multicols}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\clearpage
The source document \jobname is OVER with this 1 col page.

\end{document}

--------------------- OR ----------------------------

\documentclass[12pt,a4paper,x11names,landscape]{article}
\usepackage{lipsum,mwe}
\usepackage{incgraph,graphicx}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[spanish]{babel}

\begin{document}
The source document is\jobname.

\begin{minipage}[b]{0.45\linewidth}
\centering
\begin{figure}
  %\centering
  % Requires \usepackage{graphicx}
  \includegraphics[width=\textwidth]{example-image-a.eps}
  \caption{forma02}\label{forma02}
\end{figure}
\end{minipage}
\hspace{0.5cm}
\begin{minipage}[b]{0.45\linewidth}
Here are comments about the figure in this page
\begin{itemize}
  \item This is the first
  \item 2nd
  \item and the last
\end{itemize}
\end{minipage}

\end{document}

Answer 1

You can't use \begin{figure}...\end{figure} inside a minipage. See e.g., this question. I added the caption package and removed the figure environment.

\documentclass[12pt,a4paper,x11names,landscape]{article}
\usepackage{lipsum,mwe}
\usepackage{caption}
\usepackage{incgraph,graphicx}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[spanish]{babel}

\begin{document}
The source document is \jobname.

\begin{minipage}[b]{0.45\linewidth}
  \centering
  \includegraphics[width=\textwidth]{example-image}
  \captionof{figure}{forma02}\label{forma02}
\end{minipage}
\hspace{0.5cm}
\begin{minipage}[b]{0.45\linewidth}
Here are comments about the figure in this page
\begin{itemize}
  \item This is the first
  \item 2nd
  \item and the last
\end{itemize}
\end{minipage}

\end{document}