how to get content from other site and show it?

You can use wp_remote_get or/and wp_remote_retrieve_body functions to get HTTP response

Retrieve the raw response from the HTTP request using the GET method. Results include HTTP headers and content. codex here

$response = wp_remote_get( $url, $args );

Retrieves the body of an already retrieved HTTP request. Codex

$the_body = wp_remote_retrieve_body( wp_remote_get('http://example.com') );

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)