How do I replace the templates included in the theme to mine

1.  Create a new page in WP, name it anything other than "Portfolio",

2.  Go to Page Builder and create a new layout. 

3.  Place the shortcode in the new WP page.

4.  After that you need to create your own portfolio layout using the snapshot blocks.

5.  Then export all WP content into an xml file leaving only the items for the WP page and the page layout.