Where do I obtain a template?
The class is distributed with templates for articles in English and in French.
Perhaps the simplest way to obtain a copy of the templates is through the direct links provided in the project repository:
cjs-template.tex
for the English template;rcs-gabarit.tex
for the French template.
If you are using the version of the class included with your TeX distribution, the templates are normally installed with the documentation.
If you opted for a local or manual installation of the class, the templates reside in your project directory.