Edit /sys/app/contollers/IndexController.php add page you want as a method to class. Look at index method as example. At the end use $this->display(‘index/{your_template_file}’, $vars); place your template file name instead of {your_template_file}.
Then in your template located at /user-content/templates/{template_name}/views/index/ create template file {your_template_file} similar to index.php for example.
Then your page url will be /index/{youtmethod}
Just analyze indexController for how pages work and you will understand general structure.