EXACTLY where to insert the codes?

The tutorials doesn’t say exactly where do I insert the codes to display the values on the website?

I want to insert custom fields (Tel No, Fax No, Email, Website) on a custom post type (establishments).

I created the fields, the post type, connected the fields with the post type – everything’s done as explained in the first step of the tutorials.

I want to return all values on every post type, how? Which template or .php file do I use and how do I insert it? I use Custom Community Theme.

Please help. Thanks

https://wordpress.org/plugins/simple-fields/