Hi Amicable!
Using data explorer, the query would be:
WITH posts_by_user AS (
SELECT COUNT(*) AS posts, user_id
FROM posts
GROUP BY user_id
)
SELECT
u.id,
u.username_lower AS "username",
u.created_at,
u.last_seen_at
FROM users u
LEFT JOIN posts_by_user pbu ON pbu.user_id = u.id
WHERE u.active = true and u.trust_level = 0
AND posts IS NULL
ORDER BY u.id