But I feel I have to ask why you need to do this. If you want to integrate with a WordPress install the normal way to do that would be with a theme or plugin.

Thanks! I did more searching and I think now i need to create custom wordpress post/page templates by uploading files to child or parent theme directory so I am gonna try it now.

This way i keep post/page default structure (header etc) design and so on instead of creating my own files, in fact i wanted to include them anyway so ill try to do it this way (via inserting files to theme directory)