By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.
with rws as (
select 'lastname,firstname' str from dual
)
SELECT regexp_substr(str, '[^,]+', 1, 1) as LastName,
SUBSTR(regexp_substr(str, '[^,]+', 1, 2),1,1) as FirstNameinitial
from rws
| LASTNAME | FIRSTNAMEINITIAL |
|---|---|
| lastname | f |