I am beginner on the roots them and I am trying to wrap my head around how it works. I have searched various topics around creating templates in the forum and they all seem to talk about creating a copy of either base.php or page.php or template-custom.php.
I am bit confused here. As far as I have understood to create a template, I need to first create a copy of template-custom.php to template-mytemplate.php. Then I need to update the template/content in the file. By default it says page. So, this looks like I need to create a copy of page.php to, say, page-mypage.php and set <?php get_template_part('templates/content', 'page-mypage'); ?> in the template php file. I can then put all my HTML markup in the page-mypage.php file.
Am I thinking correctly?