Manual:Creating template

Templates are pages that are embedded (transcluded) into other pages to allow for the repetition of information. ''' This page is a guide for creating a template easily. '''

First way
If you create a page called Template:Userpage with contents: Welcome to my user page. you have created your first template! Then anyone can find that template like in any other pages.

Second way
To use HTML templates in your code at first you should create a Mustache template file with a mustache file extension for example-Myname.mustache The link of mustache is here- Mustache

You should follow these instructions to create a template- Mustache-5 specification.