with T as (
    SELECT MEMBER_CODE, MIN(LOGIN_DATETIME) LOGIN_DATETIME
    FROM ACCESS_LOG
    GROUP BY MEMBER_CODE
)

SELECT
date(LOGIN_DATETIME) as FIRST_LOGIN
,COUNT(*) as MEMBER_CNT
FROM T
WHERE LOGIN_DATETIME >= '2023-08-01' and LOGIN_DATETIME < '2023-09-01'
GROUP BY date(LOGIN_DATETIME)
ORDER BY 1 DESC