How do I prepare strings for insertions as values into a MySQL table?

dbDelta is really meant for creating databases or tables, not inserting records.

I’d suggest using $wpdb->insert(), which will escape the values for you:

$wpdb->insert( 
    $wpdb->prefix . 'w2bw2c_venue', 
    array(
        'market_id'  => 7,
        'venue_name' => get_the_title( $id ),
    ),
    array(
        '%d',
        '%s',
    )
);

I’ve just used the name field you were having trouble with in my example, obviously you’ll want to fill out the rest. I included market_id to show the correct usage of the second $format array, ensuring that market_id is parsed as an integer.