DBSQL Insert value from one entity in a column to another in different column

can u guys tell me if this is correct?? i am trying to insert the value of firstname_1 into first_name.

INSERT INTO wp_usermeta(meta_value) where meta_key=first_name
select meta_value where meta_key=firstname_1

THIS IS THE TABLE (tablename = wp_usermeta) VIEW FROM THE DATABASE

423 16 firstname_1 vrigu
424 16 lastname_2 de
425 16 gender_5 male
426 16 bankname_3 SBI
427 16 accountnumber_4 9456874526
429 17 nickname mithu123
430 17 first_name
431 17 last_name