[MySQL] Separating two rows into separate columns

I'm working on a final project for my database class, and I'm stuck on a specific task in the project. Basically, I have two tables (person & message), and I need to combine certain aspects from the databases. The instructions are pictured here https://i.imgur.com/rFLsEQy.png . The code that I have so far is this.

(SELECT 
    person.first_name AS "Sender First Name",
    person.last_name AS "Sender Last Name",
    message.message_id,
    message.message,
    message.send_datetime AS "Message Timestamp"
    FROM message
    JOIN person ON person.person_id = message.sender_id
    WHERE message.sender_id = 1)
UNION
(SELECT 
    person.first_name AS "Receiver First Name",
    person.last_name AS "Receiver Last Name",
    message.message_id,
    message.message,
    message.send_datetime AS "Message Timestamp"
    FROM message
    JOIN person ON person.person_id = message.receiver_id
    WHERE message.sender_id = 1);

& the output is https://i.imgur.com/oDc0T3s.png . I've been trying to research this for a few days and can't figure out how to separate the Receiver First and Receiver Last Name into separate columns. Any help would be appreciated, thank you.