You need to be « Administrator » of the environment to be able to create a template.
A template is a specific project which can contain:
The planning of the template can hold phases, tasks, milestones and dependencies. However, no resource can be assigned to a template (it is performed when the project is created).
You can create a template from the "Project" menu.
Then click on "Template" and "Create a new template".
You then just have to enter the description of the template.
Careful, to make a template visible for a template to be visible, you need to check the box "Available". If you don't, it means that you are still working on it and you don’t want users to use it.
You can then add elements to it, just like a project:
All these elements will be available in the future project created from the template.
The template can now be used (if you have checked the box "Available").