Anything to do with using the Google Places API is going to be off-topic here, but the best place to start would be the developer docs.
However, how you interact with the API data within WordPress is certainly on-topic. I would suggest a wrapper function that caches the results periodically:
/**
* Get places data for a post.
*
* @param int|WP_Post $post Optional, defaults to current post.
* @return mixed
*/
function wpse_187541_google_places_data( $post = null ) {
if ( ! $post = get_post( $post ) )
return;
if ( ! $place_id = get_post_meta( $post->ID, 'place_id', true ) )
return; // No place ID configured for this post
if ( $data = get_post_meta( $post->ID, 'place_data', true ) ) {
if ( $data->timeout <= current_time( 'timestamp' ) )
$data = null; // Void the cache if it's old
}
if ( ! $data ) {
$args = http_build_query(
array(
'key' => '', // API key
'placeid' => $place_id,
)
);
$http = wp_remote_get( "https://maps.googleapis.com/maps/api/place/details/json?$args" );
if ( $body = wp_remote_retrieve_body( $http ) ) {
if ( $data =@ json_decode( $body ) )
$data->timeout = current_time( 'timestamp' ) + HOUR_IN_SECONDS; // Cache data for 1 hour
}
if ( $data ) {
update_post_meta( $post->ID, 'place_data', $data );
} else {
// Something went wrong.
// Perhaps check HTTP response and decide cause of problem.
// Don't want to keep hitting the API on every call if the error is permanent (i.e. invalid place id etc.)
}
}
return $data;
}