How do I access variables outside a function [closed]

You could return the data and set a local variable:

function get_album_info() {
    $album = array(
        'art' => wp_get_attachment_image_src( get_sub_field('album_art'), 'full' ),
        'date' => get_field('album_date')
    );
    return $album;
}

$album = get_album_info();
echo $album['art'];
echo $album['date'];